Consistently use 'supertrait'.

A subset of places referred to 'super-trait', so this changes them
to all use 'supertrait'. This matches 'supertype' and some other
usages. An exception is 'auto-trait' which is consistently used
in that manner.

25 files changed, 88 insertions, 88 deletions

diff --git a/compiler/rustc_driver/src/pretty.rs b/compiler/rustc_driver/src/pretty.rs
index ff8920863b1..f5ae7e37277 100644
--- a/compiler/rustc_driver/src/pretty.rs
+++ b/compiler/rustc_driver/src/pretty.rs
@@ -88,7 +88,7 @@ trait PrinterSupport: pprust::PpAnn {
     /// Produces the pretty-print annotation object.
     ///
     /// (Rust does not yet support upcasting from a trait object to
-    /// an object for one of its super-traits.)
+    /// an object for one of its supertraits.)
     fn pp_ann(&self) -> &dyn pprust::PpAnn;
 }
 
@@ -104,7 +104,7 @@ trait HirPrinterSupport<'hir>: pprust_hir::PpAnn {
     /// Produces the pretty-print annotation object.
     ///
     /// (Rust does not yet support upcasting from a trait object to
-    /// an object for one of its super-traits.)
+    /// an object for one of its supertraits.)
     fn pp_ann(&self) -> &dyn pprust_hir::PpAnn;
 }
 
diff --git a/compiler/rustc_error_codes/src/error_codes/E0222.md b/compiler/rustc_error_codes/src/error_codes/E0222.md
index fbf1b8d7033..f929f219af4 100644
--- a/compiler/rustc_error_codes/src/error_codes/E0222.md
+++ b/compiler/rustc_error_codes/src/error_codes/E0222.md
@@ -16,9 +16,9 @@ pub trait BoxCar : Box + Vehicle {}
 fn dent_object<COLOR>(c: dyn BoxCar<Color=COLOR>) {} // Invalid constraint
 ```
 
-In this example, `BoxCar` has two super-traits: `Vehicle` and `Box`. Both of
+In this example, `BoxCar` has two supertraits: `Vehicle` and `Box`. Both of
 these traits define an associated type `Color`. `BoxCar` inherits two types
-with that name from both super-traits. Because of this, we need to use the
+with that name from both supertraits. Because of this, we need to use the
 fully qualified path syntax to refer to the appropriate `Color` associated
 type, either `<BoxCar as Vehicle>::Color` or `<BoxCar as Box>::Color`, but this
 syntax is not allowed to be used in a function signature.
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 1e8ae813336..7bee2f0c60a 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -2117,7 +2117,7 @@ impl<'tcx> TyCtxt<'tcx> {
         })
     }
 
-    /// Computes the def-ids of the transitive super-traits of `trait_def_id`. This (intentionally)
+    /// Computes the def-ids of the transitive supertraits of `trait_def_id`. This (intentionally)
     /// does not compute the full elaborated super-predicates but just the set of def-ids. It is used
     /// to identify which traits may define a given associated type to help avoid cycle errors.
     /// Returns a `DefId` iterator.
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index 7a6012409db..84b89b0c4d7 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -599,7 +599,7 @@ impl<'tcx> Predicate<'tcx> {
         //   where both `'x` and `'b` would have a DB index of 1.
         //   The substitution from the input trait-ref is therefore going to be
         //   `'a => 'x` (where `'x` has a DB index of 1).
-        // - The super-trait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an
+        // - The supertrait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an
         //   early-bound parameter and `'b' is a late-bound parameter with a
         //   DB index of 1.
         // - If we replace `'a` with `'x` from the input, it too will have
diff --git a/compiler/rustc_save_analysis/src/dump_visitor.rs b/compiler/rustc_save_analysis/src/dump_visitor.rs
index c47d8b934cf..f4567b33483 100644
--- a/compiler/rustc_save_analysis/src/dump_visitor.rs
+++ b/compiler/rustc_save_analysis/src/dump_visitor.rs
@@ -682,7 +682,7 @@ impl<'tcx> DumpVisitor<'tcx> {
             );
         }
 
-        // super-traits
+        // supertraits
         for super_bound in trait_refs.iter() {
             let (def_id, sub_span) = match *super_bound {
                 hir::GenericBound::Trait(ref trait_ref, _) => (
diff --git a/compiler/rustc_typeck/src/astconv/errors.rs b/compiler/rustc_typeck/src/astconv/errors.rs
index 695132281c6..ec75e4a55d4 100644
--- a/compiler/rustc_typeck/src/astconv/errors.rs
+++ b/compiler/rustc_typeck/src/astconv/errors.rs
@@ -199,7 +199,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
 
     /// When there are any missing associated types, emit an E0191 error and attempt to supply a
     /// reasonable suggestion on how to write it. For the case of multiple associated types in the
-    /// same trait bound have the same name (as they come from different super-traits), we instead
+    /// same trait bound have the same name (as they come from different supertraits), we instead
     /// emit a generic note suggesting using a `where` clause to constraint instead.
     pub(crate) fn complain_about_missing_associated_types(
         &self,
@@ -340,7 +340,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                          using the fully-qualified path to the associated types";
         if !where_constraints.is_empty() && suggestions.is_empty() {
             // If there are duplicates associated type names and a single trait bound do not
-            // use structured suggestion, it means that there are multiple super-traits with
+            // use structured suggestion, it means that there are multiple supertraits with
             // the same associated type name.
             err.help(where_msg);
         }
diff --git a/compiler/rustc_typeck/src/astconv/mod.rs b/compiler/rustc_typeck/src/astconv/mod.rs
index 33df541eb2b..80610b5801d 100644
--- a/compiler/rustc_typeck/src/astconv/mod.rs
+++ b/compiler/rustc_typeck/src/astconv/mod.rs
@@ -1322,7 +1322,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             );
             first_trait.label_with_exp_info(&mut err, "first non-auto trait", "first use");
             err.help(&format!(
-                "consider creating a new trait with all of these as super-traits and using that \
+                "consider creating a new trait with all of these as supertraits and using that \
                  trait here instead: `trait NewTrait: {} {{}}`",
                 regular_traits
                     .iter()
diff --git a/compiler/rustc_typeck/src/check/method/probe.rs b/compiler/rustc_typeck/src/check/method/probe.rs
index 5aa579f33a9..5a0c77de362 100644
--- a/compiler/rustc_typeck/src/check/method/probe.rs
+++ b/compiler/rustc_typeck/src/check/method/probe.rs
@@ -964,7 +964,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         let trait_ref = ty::TraitRef::new(trait_def_id, trait_substs);
 
         if self.tcx.is_trait_alias(trait_def_id) {
-            // For trait aliases, assume all super-traits are relevant.
+            // For trait aliases, assume all supertraits are relevant.
             let bounds = iter::once(ty::Binder::dummy(trait_ref));
             self.elaborate_bounds(bounds, |this, new_trait_ref, item| {
                 let new_trait_ref = this.erase_late_bound_regions(new_trait_ref);
diff --git a/src/test/ui/associated-type-bounds/super-trait-referencing-self.rs b/src/test/ui/associated-type-bounds/supertrait-referencing-self.rs
index c82ec01f4d6..c82ec01f4d6 100644
--- a/src/test/ui/associated-type-bounds/super-trait-referencing-self.rs
+++ b/src/test/ui/associated-type-bounds/supertrait-referencing-self.rs
diff --git a/src/test/ui/associated-type-bounds/super-trait-referencing.rs b/src/test/ui/associated-type-bounds/supertrait-referencing.rs
index 2e97535157f..2e97535157f 100644
--- a/src/test/ui/associated-type-bounds/super-trait-referencing.rs
+++ b/src/test/ui/associated-type-bounds/supertrait-referencing.rs
diff --git a/src/test/ui/associated-type-bounds/super-trait-where-referencing-self.rs b/src/test/ui/associated-type-bounds/supertrait-where-referencing-self.rs
index 72a6be9ffc3..72a6be9ffc3 100644
--- a/src/test/ui/associated-type-bounds/super-trait-where-referencing-self.rs
+++ b/src/test/ui/associated-type-bounds/supertrait-where-referencing-self.rs
diff --git a/src/test/ui/associated-types/issue-22560.stderr b/src/test/ui/associated-types/issue-22560.stderr
index d2193cc4a48..c5c70f226fd 100644
--- a/src/test/ui/associated-types/issue-22560.stderr
+++ b/src/test/ui/associated-types/issue-22560.stderr
@@ -32,7 +32,7 @@ LL | type Test = dyn Add + Sub;
    |                 |
    |                 first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Add<[type error]> + Sub<[type error]> {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Add<[type error]> + Sub<[type error]> {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0191]: the value of the associated types `Output` (from trait `Add`), `Output` (from trait `Sub`) must be specified
diff --git a/src/test/ui/associated-types/missing-associated-types.stderr b/src/test/ui/associated-types/missing-associated-types.stderr
index 340d4e2418e..8c52736b02c 100644
--- a/src/test/ui/associated-types/missing-associated-types.stderr
+++ b/src/test/ui/associated-types/missing-associated-types.stderr
@@ -6,7 +6,7 @@ LL | type Foo<Rhs> = dyn Add<Rhs> + Sub<Rhs> + X<Rhs> + Y<Rhs>;
    |                     |
    |                     first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Add<Rhs> + Sub<Rhs> + X<Rhs> + Y<Rhs> {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Add<Rhs> + Sub<Rhs> + X<Rhs> + Y<Rhs> {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0191]: the value of the associated types `A` (from trait `Y`), `Output` (from trait `Add`), `Output` (from trait `Mul`), `Output` (from trait `Sub`) must be specified
@@ -35,7 +35,7 @@ LL | type Bar<Rhs> = dyn Add<Rhs> + Sub<Rhs> + X<Rhs> + Z<Rhs>;
    |                     |
    |                     first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Add<Rhs> + Sub<Rhs> + X<Rhs> + Z<Rhs> {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Add<Rhs> + Sub<Rhs> + X<Rhs> + Z<Rhs> {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0191]: the value of the associated types `A` (from trait `Z`), `B` (from trait `Z`), `Output` (from trait `Add`), `Output` (from trait `Div`), `Output` (from trait `Div`), `Output` (from trait `Mul`), `Output` (from trait `Sub`) must be specified
@@ -71,7 +71,7 @@ LL | type Baz<Rhs> = dyn Add<Rhs> + Sub<Rhs> + Y<Rhs>;
    |                     |
    |                     first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Add<Rhs> + Sub<Rhs> + Y<Rhs> {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Add<Rhs> + Sub<Rhs> + Y<Rhs> {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0191]: the value of the associated types `A` (from trait `Y`), `Output` (from trait `Add`), `Output` (from trait `Sub`) must be specified
@@ -99,7 +99,7 @@ LL | type Bat<Rhs> = dyn Add<Rhs> + Sub<Rhs> + Fine<Rhs>;
    |                     |
    |                     first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Add<Rhs> + Sub<Rhs> + Fine<Rhs> {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Add<Rhs> + Sub<Rhs> + Fine<Rhs> {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0191]: the value of the associated types `Output` (from trait `Add`), `Output` (from trait `Sub`) must be specified
diff --git a/src/test/ui/error-codes/E0225.stderr b/src/test/ui/error-codes/E0225.stderr
index 435a2c93962..a4b33a0b7b4 100644
--- a/src/test/ui/error-codes/E0225.stderr
+++ b/src/test/ui/error-codes/E0225.stderr
@@ -6,7 +6,7 @@ LL |     let _: Box<dyn std::io::Read + std::io::Write>;
    |                    |
    |                    first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: std::io::Read + std::io::Write {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: std::io::Read + std::io::Write {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -23,7 +23,7 @@ LL |     let _: Box<dyn Foo>;
    |                    trait alias used in trait object type (additional use)
    |                    trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: std::io::Read + std::io::Write {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: std::io::Read + std::io::Write {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error: aborting due to 2 previous errors
diff --git a/src/test/ui/issues/issue-32963.stderr b/src/test/ui/issues/issue-32963.stderr
index b5aa7b1b94d..5e7762b3220 100644
--- a/src/test/ui/issues/issue-32963.stderr
+++ b/src/test/ui/issues/issue-32963.stderr
@@ -6,7 +6,7 @@ LL |     size_of_copy::<dyn Misc + Copy>();
    |                        |
    |                        first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Misc + Copy {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Misc + Copy {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -17,7 +17,7 @@ LL |     size_of_copy::<dyn Misc + Copy>();
    |                        |
    |                        first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Misc + Copy {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Misc + Copy {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0277]: the trait bound `dyn Misc: Copy` is not satisfied
diff --git a/src/test/ui/parser/trait-object-delimiters.stderr b/src/test/ui/parser/trait-object-delimiters.stderr
index ee638d8a4f5..75eeeda8646 100644
--- a/src/test/ui/parser/trait-object-delimiters.stderr
+++ b/src/test/ui/parser/trait-object-delimiters.stderr
@@ -52,7 +52,7 @@ LL | fn foo1(_: &dyn Drop + AsRef<str>) {}
    |                 |
    |                 first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Drop + AsRef<str> {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Drop + AsRef<str> {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0224]: at least one trait is required for an object type
@@ -69,7 +69,7 @@ LL | fn foo5(_: &(dyn Drop + dyn AsRef<str>)) {}
    |                  |
    |                  first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Drop + AsRef<str> {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Drop + AsRef<str> {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error: aborting due to 9 previous errors
diff --git a/src/test/ui/parser/trait-object-trait-parens.stderr b/src/test/ui/parser/trait-object-trait-parens.stderr
index b39fe4646a3..657288c70f3 100644
--- a/src/test/ui/parser/trait-object-trait-parens.stderr
+++ b/src/test/ui/parser/trait-object-trait-parens.stderr
@@ -52,7 +52,7 @@ LL |     let _: Box<(Obj) + (?Sized) + (for<'a> Trait<'a>)>;
    |                |
    |                first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + for<'a> Trait<'a> {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + for<'a> Trait<'a> {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -63,7 +63,7 @@ LL |     let _: Box<?Sized + (for<'a> Trait<'a>) + (Obj)>;
    |                         |
    |                         first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: for<'a> Trait<'a> + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: for<'a> Trait<'a> + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -74,7 +74,7 @@ LL |     let _: Box<for<'a> Trait<'a> + (Obj) + (?Sized)>;
    |                |
    |                first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: for<'a> Trait<'a> + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: for<'a> Trait<'a> + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error: aborting due to 6 previous errors; 3 warnings emitted
diff --git a/src/test/ui/specialization/README-rpass.md b/src/test/ui/specialization/README-rpass.md
index 1373a2cf81b..c1486ce1ee8 100644
--- a/src/test/ui/specialization/README-rpass.md
+++ b/src/test/ui/specialization/README-rpass.md
@@ -8,7 +8,7 @@ Tests that specialization is working correctly:
     - Specialization via concrete types vs unknown types
       - In top level of the trait reference
       - Embedded within another type (`Vec<T>` vs `Vec<i32>`)
-  - [Specialization based on super trait relationships](specialization-super-traits.rs)
+  - [Specialization based on super trait relationships](specialization-supertraits.rs)
   - [On assoc fns](specialization-assoc-fns.rs)
   - [Ensure that impl order doesn't matter](specialization-out-of-order.rs)
 
diff --git a/src/test/ui/specialization/specialization-super-traits.rs b/src/test/ui/specialization/specialization-supertraits.rs
index fb85d801921..fb85d801921 100644
--- a/src/test/ui/specialization/specialization-super-traits.rs
+++ b/src/test/ui/specialization/specialization-supertraits.rs
diff --git a/src/test/ui/specialization/specialization-super-traits.stderr b/src/test/ui/specialization/specialization-supertraits.stderr
index 165703d6365..d32e47a24c2 100644
--- a/src/test/ui/specialization/specialization-super-traits.stderr
+++ b/src/test/ui/specialization/specialization-supertraits.stderr
@@ -1,5 +1,5 @@
 warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
-  --> $DIR/specialization-super-traits.rs:3:12
+  --> $DIR/specialization-supertraits.rs:3:12
    |
 LL | #![feature(specialization)]
    |            ^^^^^^^^^^^^^^
diff --git a/src/test/ui/traits/alias/no-duplicates.stderr b/src/test/ui/traits/alias/no-duplicates.stderr
index 9f38dd40c3a..d3002db46a2 100644
--- a/src/test/ui/traits/alias/no-duplicates.stderr
+++ b/src/test/ui/traits/alias/no-duplicates.stderr
@@ -12,7 +12,7 @@ LL | type _T00 = dyn _0 + _0;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -31,7 +31,7 @@ LL | type _T01 = dyn _1 + _0;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -53,7 +53,7 @@ LL | type _T02 = dyn _1 + _1;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -69,7 +69,7 @@ LL | type _T03 = dyn Obj + _1;
    |                 |
    |                 first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -85,7 +85,7 @@ LL | type _T04 = dyn _1 + Obj;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -110,7 +110,7 @@ LL | type _T10 = dyn _2 + _3;
    |                 trait alias used in trait object type (additional use)
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -129,7 +129,7 @@ LL | type _T11 = dyn _3 + _2;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -146,7 +146,7 @@ LL | type _T12 = dyn Obj + _2;
    |                 |
    |                 first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -171,7 +171,7 @@ LL | type _T13 = dyn _2 + Obj;
    |                 trait alias used in trait object type (additional use)
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -190,7 +190,7 @@ LL | type _T14 = dyn _1 + _3;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -209,7 +209,7 @@ LL | type _T15 = dyn _3 + _1;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -230,7 +230,7 @@ LL | type _T16 = dyn _1 + _4;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -251,7 +251,7 @@ LL | type _T17 = dyn _4 + _1;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -268,7 +268,7 @@ LL | type _T20 = dyn _5 + _5;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -282,7 +282,7 @@ LL | type _T21 = dyn Obj + _5;
    |                 |
    |                 first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -296,7 +296,7 @@ LL | type _T22 = dyn _5 + Obj;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -310,7 +310,7 @@ LL | type _T23 = dyn _5 + Send + Sync + Obj;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -333,7 +333,7 @@ LL | type _T30 = dyn _6;
    |                 trait alias used in trait object type (additional use)
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -356,7 +356,7 @@ LL | type _T31 = dyn _6 + Send;
    |                 trait alias used in trait object type (additional use)
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -379,7 +379,7 @@ LL | type _T32 = dyn Send + _6;
    |                        trait alias used in trait object type (additional use)
    |                        trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -398,7 +398,7 @@ LL | type _T40 = dyn _8 + Obj;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -417,7 +417,7 @@ LL | type _T41 = dyn Obj + _8;
    |                 |
    |                 first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -441,7 +441,7 @@ LL | type _T42 = dyn _8 + _4;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -465,7 +465,7 @@ LL | type _T43 = dyn _4 + _8;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -489,7 +489,7 @@ LL | type _T44 = dyn _4 + Send + Sync + _8;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -504,7 +504,7 @@ LL | type _T50 = dyn _9 + _10;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: for<'a> ObjL<'a> + for<'b> ObjL<'b> {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: for<'a> ObjL<'a> + for<'b> ObjL<'b> {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -519,7 +519,7 @@ LL | type _T60 = dyn _11 + _12;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjT<for<'a> fn(&'a u8)> + ObjT<for<'b> fn(&'b u8)> {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjT<for<'a> fn(&'a u8)> + ObjT<for<'b> fn(&'b u8)> {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error: aborting due to 27 previous errors
diff --git a/src/test/ui/traits/alias/no-extra-traits.stderr b/src/test/ui/traits/alias/no-extra-traits.stderr
index cdb5cd90b85..eaba70d7ce3 100644
--- a/src/test/ui/traits/alias/no-extra-traits.stderr
+++ b/src/test/ui/traits/alias/no-extra-traits.stderr
@@ -9,7 +9,7 @@ LL | type _T00 = dyn _0 + ObjB;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -23,7 +23,7 @@ LL | type _T01 = dyn ObjB + _0;
    |                 |
    |                 first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -39,7 +39,7 @@ LL | type _T02 = dyn ObjB + _1;
    |                 |
    |                 first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -55,7 +55,7 @@ LL | type _T03 = dyn _1 + ObjB;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -74,7 +74,7 @@ LL | type _T10 = dyn _2 + _3;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjB + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjB + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -93,7 +93,7 @@ LL | type _T11 = dyn _3 + _2;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjB + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjB + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -114,7 +114,7 @@ LL | type _T12 = dyn _2 + _4;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjB + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjB + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -135,7 +135,7 @@ LL | type _T13 = dyn _4 + _2;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjB + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjB + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -154,7 +154,7 @@ LL | type _T20 = dyn _5 + _1;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -173,7 +173,7 @@ LL | type _T21 = dyn _1 + _5;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -187,7 +187,7 @@ LL | type _T22 = dyn _5 + ObjA;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -201,7 +201,7 @@ LL | type _T23 = dyn ObjA + _5;
    |                 |
    |                 first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -220,7 +220,7 @@ LL | type _T24 = dyn Send + _5 + _1 + Sync;
    |                        |
    |                        trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -239,7 +239,7 @@ LL | type _T25 = dyn _1 + Sync + _5 + Send;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -253,7 +253,7 @@ LL | type _T26 = dyn Sync + Send + _5 + ObjA;
    |                               |
    |                               trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -267,7 +267,7 @@ LL | type _T27 = dyn Send + Sync + ObjA + _5;
    |                               |
    |                               first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -292,7 +292,7 @@ LL | type _T30 = dyn _6;
    |                 trait alias used in trait object type (additional use)
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -317,7 +317,7 @@ LL | type _T31 = dyn _6 + Send;
    |                 trait alias used in trait object type (additional use)
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -342,7 +342,7 @@ LL | type _T32 = dyn Send + _6;
    |                        trait alias used in trait object type (additional use)
    |                        trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -377,7 +377,7 @@ LL | type _T33 = dyn _8;
    |                 trait alias used in trait object type (additional use)
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -412,7 +412,7 @@ LL | type _T34 = dyn _8 + Send;
    |                 trait alias used in trait object type (additional use)
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -447,7 +447,7 @@ LL | type _T35 = dyn Send + _8;
    |                        trait alias used in trait object type (additional use)
    |                        trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -466,7 +466,7 @@ LL | type _T40 = dyn _10 + ObjA;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -485,7 +485,7 @@ LL | type _T41 = dyn ObjA + _10;
    |                 |
    |                 first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -509,7 +509,7 @@ LL | type _T42 = dyn _10 + _1;
    |                 |
    |                 trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -528,7 +528,7 @@ LL | type _T43 = dyn Send + _10 + Sync + ObjA;
    |                        |
    |                        trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -547,7 +547,7 @@ LL | type _T44 = dyn ObjA + _10 + Send + Sync;
    |                 |
    |                 first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjA + ObjB {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -571,7 +571,7 @@ LL | type _T45 = dyn Sync + Send + _10 + _1;
    |                               |
    |                               trait alias used in trait object type (first use)
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjB + ObjA {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error: aborting due to 28 previous errors
diff --git a/src/test/ui/traits/bad-sized.stderr b/src/test/ui/traits/bad-sized.stderr
index 1322b660035..5421e71509f 100644
--- a/src/test/ui/traits/bad-sized.stderr
+++ b/src/test/ui/traits/bad-sized.stderr
@@ -6,7 +6,7 @@ LL |     let x: Vec<dyn Trait + Sized> = Vec::new();
    |                    |
    |                    first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Trait + Sized {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Trait + Sized {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0277]: the size for values of type `dyn Trait` cannot be known at compilation time
diff --git a/src/test/ui/traits/normalize-super-trait.rs b/src/test/ui/traits/normalize-supertrait.rs
index 021a93eacff..021a93eacff 100644
--- a/src/test/ui/traits/normalize-super-trait.rs
+++ b/src/test/ui/traits/normalize-supertrait.rs
diff --git a/src/test/ui/traits/wf-object/no-duplicates.stderr b/src/test/ui/traits/wf-object/no-duplicates.stderr
index b9506894f82..50dfcf95636 100644
--- a/src/test/ui/traits/wf-object/no-duplicates.stderr
+++ b/src/test/ui/traits/wf-object/no-duplicates.stderr
@@ -6,7 +6,7 @@ LL | type _0 = dyn Obj + Obj;
    |               |
    |               first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -17,7 +17,7 @@ LL | type _1 = dyn Send + Obj + Obj;
    |                      |
    |                      first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -28,7 +28,7 @@ LL | type _2 = dyn Obj + Send + Obj;
    |               |
    |               first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Obj + Obj {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -39,7 +39,7 @@ LL | type _4 = dyn for<'a> ObjL<'a> + for<'b> ObjL<'b>;
    |               |
    |               first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: for<'a> ObjL<'a> + for<'b> ObjL<'b> {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: for<'a> ObjL<'a> + for<'b> ObjL<'b> {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
@@ -50,7 +50,7 @@ LL | type _5 = dyn ObjT<for<'a> fn(&'a u8)> + ObjT<for<'b> fn(&'b u8)>;
    |               |
    |               first non-auto trait
    |
-   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: ObjT<for<'a> fn(&'a u8)> + ObjT<for<'b> fn(&'b u8)> {}`
+   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: ObjT<for<'a> fn(&'a u8)> + ObjT<for<'b> fn(&'b u8)> {}`
    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
 
 error: aborting due to 5 previous errors