Don't reject *multiple* relaxed bounds, reject *duplicate* ones.

Having multiple relaxed bounds like `?Sized + ?Iterator` is actually *fine*.
We actually want to reject *duplicate* relaxed bounds like `?Sized + ?Sized`
because these most certainly represent a user error.

Note that this doesn't mean that we accept more code because a bound like
`?Iterator` is still invalid as it's not relaxing a *default* trait and
the only way to define / use more default bounds is under the experimental
and internal feature `more_maybe_bounds` plus `lang_items` plus unstable
flag `-Zexperimental-default-bounds` (historical context: for the longest
time, bounds like `?Iterator` were actually allowed and lead to a hard
warning).

Ultimately, this simply *reframes* the diagnostic. The scope of
`more_maybe_bounds` / `-Zexperimental-default-bounds` remains unchanged
as well.

15 files changed, 128 insertions, 150 deletions

diff --git a/compiler/rustc_error_codes/src/error_codes/E0203.md b/compiler/rustc_error_codes/src/error_codes/E0203.md
index 1edb519275f..a4dceedbf1f 100644
--- a/compiler/rustc_error_codes/src/error_codes/E0203.md
+++ b/compiler/rustc_error_codes/src/error_codes/E0203.md
@@ -1,15 +1,15 @@
-Having multiple relaxed default bounds is unsupported.
+Having duplicate relaxed default bounds is unsupported.
 
 Erroneous code example:
 
 ```compile_fail,E0203
-struct Bad<T: ?Sized + ?Send>{
-    inner: T
+struct Bad<T: ?Sized + ?Sized>{
+    inner: T,
 }
 ```
 
-Here the type `T` cannot have a relaxed bound for multiple default traits
-(`Sized` and `Send`). This can be fixed by only using one relaxed bound.
+Here the type parameter `T` cannot have duplicate relaxed bounds for default
+trait `Sized`. This can be fixed by only using one relaxed bound:
 
 ```
 struct Good<T: ?Sized>{
diff --git a/compiler/rustc_hir_analysis/messages.ftl b/compiler/rustc_hir_analysis/messages.ftl
index a20becbe7e8..90cb1727034 100644
--- a/compiler/rustc_hir_analysis/messages.ftl
+++ b/compiler/rustc_hir_analysis/messages.ftl
@@ -371,9 +371,6 @@ hir_analysis_missing_type_params =
         *[other] parameters
     } must be specified on the object type
 
-hir_analysis_multiple_relaxed_default_bounds =
-    type parameter has more than one relaxed default bound, only one is supported
-
 hir_analysis_must_be_name_of_associated_function = must be a name of an associated function
 
 hir_analysis_must_implement_not_function = not a function
diff --git a/compiler/rustc_hir_analysis/src/errors.rs b/compiler/rustc_hir_analysis/src/errors.rs
index eb65050c17c..3283ce95ee0 100644
--- a/compiler/rustc_hir_analysis/src/errors.rs
+++ b/compiler/rustc_hir_analysis/src/errors.rs
@@ -279,13 +279,6 @@ pub(crate) struct CopyImplOnTypeWithDtor {
 }
 
 #[derive(Diagnostic)]
-#[diag(hir_analysis_multiple_relaxed_default_bounds, code = E0203)]
-pub(crate) struct MultipleRelaxedDefaultBounds {
-    #[primary_span]
-    pub spans: Vec<Span>,
-}
-
-#[derive(Diagnostic)]
 #[diag(hir_analysis_copy_impl_on_non_adt, code = E0206)]
 pub(crate) struct CopyImplOnNonAdt {
     #[primary_span]
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
index 8c99a41f626..3db78db931a 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
@@ -35,31 +35,29 @@ use crate::fluent_generated as fluent;
 use crate::hir_ty_lowering::{AssocItemQSelf, HirTyLowerer};
 
 impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
-    /// Check for multiple relaxed bounds and relaxed bounds of non-default traits.
+    /// Check for duplicate relaxed bounds and relaxed bounds of non-default traits.
     pub(crate) fn check_and_report_invalid_relaxed_bounds(
         &self,
         relaxed_bounds: SmallVec<[&PolyTraitRef<'_>; 1]>,
     ) {
         let tcx = self.tcx();
 
-        let mut unique_bounds = FxIndexSet::default();
-        let mut seen_repeat = false;
+        let mut grouped_bounds = FxIndexMap::<_, Vec<_>>::default();
+
         for bound in &relaxed_bounds {
             if let Res::Def(DefKind::Trait, trait_def_id) = bound.trait_ref.path.res {
-                seen_repeat |= !unique_bounds.insert(trait_def_id);
+                grouped_bounds.entry(trait_def_id).or_default().push(bound.span);
             }
         }
 
-        if relaxed_bounds.len() > 1 {
-            let err = errors::MultipleRelaxedDefaultBounds {
-                spans: relaxed_bounds.iter().map(|ptr| ptr.span).collect(),
-            };
-
-            if seen_repeat {
-                tcx.dcx().emit_err(err);
-            } else if !tcx.features().more_maybe_bounds() {
-                tcx.sess.create_feature_err(err, sym::more_maybe_bounds).emit();
-            };
+        for (trait_def_id, spans) in grouped_bounds {
+            if spans.len() > 1 {
+                let name = tcx.item_name(trait_def_id);
+                self.dcx()
+                    .struct_span_err(spans, format!("duplicate relaxed `{name}` bounds"))
+                    .with_code(E0203)
+                    .emit();
+            }
         }
 
         let sized_def_id = tcx.require_lang_item(hir::LangItem::Sized, DUMMY_SP);
diff --git a/tests/ui/feature-gates/feature-gate-more-maybe-bounds.rs b/tests/ui/feature-gates/feature-gate-more-maybe-bounds.rs
index 7c9d88462f6..9c727ae3aad 100644
--- a/tests/ui/feature-gates/feature-gate-more-maybe-bounds.rs
+++ b/tests/ui/feature-gates/feature-gate-more-maybe-bounds.rs
@@ -8,15 +8,7 @@ trait Trait4 where Self: ?Trait1 {} //~ ERROR this relaxed bound is not permitte
 fn foo(_: Box<dyn Trait1 + ?Trait2>) {}
 //~^  ERROR relaxed bounds are not permitted in trait object types
 fn bar<T: ?Trait1 + ?Trait2>(_: T) {}
-//~^ ERROR type parameter has more than one relaxed default bound, only one is supported
-//~| ERROR bound modifier `?` can only be applied to `Sized`
-//~| ERROR bound modifier `?` can only be applied to `Sized`
-
-trait Trait {}
-// Do not suggest `#![feature(more_maybe_bounds)]` for repetitions
-fn baz<T: ?Trait + ?Trait>(_ : T) {}
-//~^ ERROR type parameter has more than one relaxed default bound, only one is supported
-//~| ERROR bound modifier `?` can only be applied to `Sized`
+//~^ ERROR bound modifier `?` can only be applied to `Sized`
 //~| ERROR bound modifier `?` can only be applied to `Sized`
 
 fn main() {}
diff --git a/tests/ui/feature-gates/feature-gate-more-maybe-bounds.stderr b/tests/ui/feature-gates/feature-gate-more-maybe-bounds.stderr
index c6d940db57b..da6ad5f16e2 100644
--- a/tests/ui/feature-gates/feature-gate-more-maybe-bounds.stderr
+++ b/tests/ui/feature-gates/feature-gate-more-maybe-bounds.stderr
@@ -18,15 +18,6 @@ error: relaxed bounds are not permitted in trait object types
 LL | fn foo(_: Box<dyn Trait1 + ?Trait2>) {}
    |                            ^^^^^^^
 
-error[E0203]: type parameter has more than one relaxed default bound, only one is supported
-  --> $DIR/feature-gate-more-maybe-bounds.rs:10:11
-   |
-LL | fn bar<T: ?Trait1 + ?Trait2>(_: T) {}
-   |           ^^^^^^^   ^^^^^^^
-   |
-   = help: add `#![feature(more_maybe_bounds)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-
 error: bound modifier `?` can only be applied to `Sized`
   --> $DIR/feature-gate-more-maybe-bounds.rs:10:11
    |
@@ -39,24 +30,5 @@ error: bound modifier `?` can only be applied to `Sized`
 LL | fn bar<T: ?Trait1 + ?Trait2>(_: T) {}
    |                     ^^^^^^^
 
-error[E0203]: type parameter has more than one relaxed default bound, only one is supported
-  --> $DIR/feature-gate-more-maybe-bounds.rs:17:11
-   |
-LL | fn baz<T: ?Trait + ?Trait>(_ : T) {}
-   |           ^^^^^^   ^^^^^^
-
-error: bound modifier `?` can only be applied to `Sized`
-  --> $DIR/feature-gate-more-maybe-bounds.rs:17:11
-   |
-LL | fn baz<T: ?Trait + ?Trait>(_ : T) {}
-   |           ^^^^^^
-
-error: bound modifier `?` can only be applied to `Sized`
-  --> $DIR/feature-gate-more-maybe-bounds.rs:17:20
-   |
-LL | fn baz<T: ?Trait + ?Trait>(_ : T) {}
-   |                    ^^^^^^
-
-error: aborting due to 9 previous errors
+error: aborting due to 5 previous errors
 
-For more information about this error, try `rustc --explain E0203`.
diff --git a/tests/ui/trait-bounds/duplicate-relaxed-bounds.rs b/tests/ui/trait-bounds/duplicate-relaxed-bounds.rs
new file mode 100644
index 00000000000..a1681ddec77
--- /dev/null
+++ b/tests/ui/trait-bounds/duplicate-relaxed-bounds.rs
@@ -0,0 +1,22 @@
+fn dupes<T: ?Sized + ?Sized + ?Iterator + ?Iterator>() {}
+//~^ ERROR duplicate relaxed `Sized` bounds
+//~| ERROR duplicate relaxed `Iterator` bounds
+//~| ERROR bound modifier `?` can only be applied to `Sized`
+//~| ERROR bound modifier `?` can only be applied to `Sized`
+
+trait Trait {
+    // We used to say "type parameter has more than one relaxed default bound"
+    // even on *associated types* like here. Test that we no longer do that.
+    type Type: ?Sized + ?Sized;
+    //~^ ERROR duplicate relaxed `Sized` bounds
+    //~| ERROR duplicate relaxed `Sized` bounds
+}
+
+// We used to emit an additional error about "multiple relaxed default bounds".
+// However, multiple relaxed bounds are actually *fine* if they're distinct.
+// Ultimately, we still reject this because `Sized` is
+// the only (stable) default trait, so we're fine.
+fn not_dupes<T: ?Sized + ?Iterator>() {}
+//~^ ERROR bound modifier `?` can only be applied to `Sized`
+
+fn main() {}
diff --git a/tests/ui/trait-bounds/duplicate-relaxed-bounds.stderr b/tests/ui/trait-bounds/duplicate-relaxed-bounds.stderr
new file mode 100644
index 00000000000..ccc723fc7a6
--- /dev/null
+++ b/tests/ui/trait-bounds/duplicate-relaxed-bounds.stderr
@@ -0,0 +1,47 @@
+error[E0203]: duplicate relaxed `Sized` bounds
+  --> $DIR/duplicate-relaxed-bounds.rs:1:13
+   |
+LL | fn dupes<T: ?Sized + ?Sized + ?Iterator + ?Iterator>() {}
+   |             ^^^^^^   ^^^^^^
+
+error[E0203]: duplicate relaxed `Iterator` bounds
+  --> $DIR/duplicate-relaxed-bounds.rs:1:31
+   |
+LL | fn dupes<T: ?Sized + ?Sized + ?Iterator + ?Iterator>() {}
+   |                               ^^^^^^^^^   ^^^^^^^^^
+
+error: bound modifier `?` can only be applied to `Sized`
+  --> $DIR/duplicate-relaxed-bounds.rs:1:31
+   |
+LL | fn dupes<T: ?Sized + ?Sized + ?Iterator + ?Iterator>() {}
+   |                               ^^^^^^^^^
+
+error: bound modifier `?` can only be applied to `Sized`
+  --> $DIR/duplicate-relaxed-bounds.rs:1:43
+   |
+LL | fn dupes<T: ?Sized + ?Sized + ?Iterator + ?Iterator>() {}
+   |                                           ^^^^^^^^^
+
+error: bound modifier `?` can only be applied to `Sized`
+  --> $DIR/duplicate-relaxed-bounds.rs:19:26
+   |
+LL | fn not_dupes<T: ?Sized + ?Iterator>() {}
+   |                          ^^^^^^^^^
+
+error[E0203]: duplicate relaxed `Sized` bounds
+  --> $DIR/duplicate-relaxed-bounds.rs:10:16
+   |
+LL |     type Type: ?Sized + ?Sized;
+   |                ^^^^^^   ^^^^^^
+
+error[E0203]: duplicate relaxed `Sized` bounds
+  --> $DIR/duplicate-relaxed-bounds.rs:10:16
+   |
+LL |     type Type: ?Sized + ?Sized;
+   |                ^^^^^^   ^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
+error: aborting due to 7 previous errors
+
+For more information about this error, try `rustc --explain E0203`.
diff --git a/tests/ui/trait-bounds/bad-suggestionf-for-repeated-unsized-bound-127441.rs b/tests/ui/trait-bounds/fix-dyn-sized-fn-param-sugg.rs
index e6d7f74880f..1aa36207bc3 100644
--- a/tests/ui/trait-bounds/bad-suggestionf-for-repeated-unsized-bound-127441.rs
+++ b/tests/ui/trait-bounds/fix-dyn-sized-fn-param-sugg.rs
@@ -1,39 +1,38 @@
-// Regression test for #127441
-
-// Tests that we make the correct suggestion
-// in case there are more than one `?Sized`
-// bounds on a function parameter
+// Test that we emit a correct structured suggestions for dynamically sized ("maybe unsized")
+// function parameters.
+// We used to emit a butchered suggestion if duplicate relaxed `Sized` bounds were present.
+// issue: <https://github.com/rust-lang/rust/issues/127441>.
 
 use std::fmt::Debug;
 
 fn foo1<T: ?Sized>(a: T) {}
-//~^ ERROR he size for values of type `T` cannot be known at compilation time
+//~^ ERROR the size for values of type `T` cannot be known at compilation time
 
 fn foo2<T: ?Sized + ?Sized>(a: T) {}
-//~^ ERROR type parameter has more than one relaxed default bound, only one is supported
+//~^ ERROR duplicate relaxed `Sized` bounds
 //~| ERROR the size for values of type `T` cannot be known at compilation time
 
 fn foo3<T: ?Sized + ?Sized + Debug>(a: T) {}
-//~^ ERROR type parameter has more than one relaxed default bound, only one is supported
-//~| ERROR he size for values of type `T` cannot be known at compilation time
+//~^ ERROR duplicate relaxed `Sized` bounds
+//~| ERROR the size for values of type `T` cannot be known at compilation time
 
 fn foo4<T: ?Sized + Debug + ?Sized >(a: T) {}
-//~^ ERROR type parameter has more than one relaxed default bound, only one is supported
+//~^ ERROR duplicate relaxed `Sized` bounds
 //~| ERROR the size for values of type `T` cannot be known at compilation time
 
 fn foo5(_: impl ?Sized) {}
 //~^ ERROR the size for values of type `impl ?Sized` cannot be known at compilation time
 
 fn foo6(_: impl ?Sized + ?Sized) {}
-//~^ ERROR type parameter has more than one relaxed default bound, only one is supported
+//~^ ERROR duplicate relaxed `Sized` bounds
 //~| ERROR the size for values of type `impl ?Sized + ?Sized` cannot be known at compilation tim
 
 fn foo7(_: impl ?Sized + ?Sized + Debug) {}
-//~^ ERROR type parameter has more than one relaxed default bound, only one is supported
+//~^ ERROR duplicate relaxed `Sized` bounds
 //~| ERROR the size for values of type `impl ?Sized + ?Sized + Debug` cannot be known at compilation time
 
 fn foo8(_: impl ?Sized + Debug + ?Sized ) {}
-//~^ ERROR type parameter has more than one relaxed default bound, only one is supported
+//~^ ERROR duplicate relaxed `Sized` bounds
 //~| ERROR the size for values of type `impl ?Sized + Debug + ?Sized` cannot be known at compilation time
 
 fn main() {}
diff --git a/tests/ui/trait-bounds/bad-suggestionf-for-repeated-unsized-bound-127441.stderr b/tests/ui/trait-bounds/fix-dyn-sized-fn-param-sugg.stderr
index 363f52d6df8..7a9c2f043ac 100644
--- a/tests/ui/trait-bounds/bad-suggestionf-for-repeated-unsized-bound-127441.stderr
+++ b/tests/ui/trait-bounds/fix-dyn-sized-fn-param-sugg.stderr
@@ -1,41 +1,41 @@
-error[E0203]: type parameter has more than one relaxed default bound, only one is supported
-  --> $DIR/bad-suggestionf-for-repeated-unsized-bound-127441.rs:12:12
+error[E0203]: duplicate relaxed `Sized` bounds
+  --> $DIR/fix-dyn-sized-fn-param-sugg.rs:11:12
    |
 LL | fn foo2<T: ?Sized + ?Sized>(a: T) {}
    |            ^^^^^^   ^^^^^^
 
-error[E0203]: type parameter has more than one relaxed default bound, only one is supported
-  --> $DIR/bad-suggestionf-for-repeated-unsized-bound-127441.rs:16:12
+error[E0203]: duplicate relaxed `Sized` bounds
+  --> $DIR/fix-dyn-sized-fn-param-sugg.rs:15:12
    |
 LL | fn foo3<T: ?Sized + ?Sized + Debug>(a: T) {}
    |            ^^^^^^   ^^^^^^
 
-error[E0203]: type parameter has more than one relaxed default bound, only one is supported
-  --> $DIR/bad-suggestionf-for-repeated-unsized-bound-127441.rs:20:12
+error[E0203]: duplicate relaxed `Sized` bounds
+  --> $DIR/fix-dyn-sized-fn-param-sugg.rs:19:12
    |
 LL | fn foo4<T: ?Sized + Debug + ?Sized >(a: T) {}
    |            ^^^^^^           ^^^^^^
 
-error[E0203]: type parameter has more than one relaxed default bound, only one is supported
-  --> $DIR/bad-suggestionf-for-repeated-unsized-bound-127441.rs:27:17
+error[E0203]: duplicate relaxed `Sized` bounds
+  --> $DIR/fix-dyn-sized-fn-param-sugg.rs:26:17
    |
 LL | fn foo6(_: impl ?Sized + ?Sized) {}
    |                 ^^^^^^   ^^^^^^
 
-error[E0203]: type parameter has more than one relaxed default bound, only one is supported
-  --> $DIR/bad-suggestionf-for-repeated-unsized-bound-127441.rs:31:17
+error[E0203]: duplicate relaxed `Sized` bounds
+  --> $DIR/fix-dyn-sized-fn-param-sugg.rs:30:17
    |
 LL | fn foo7(_: impl ?Sized + ?Sized + Debug) {}
    |                 ^^^^^^   ^^^^^^
 
-error[E0203]: type parameter has more than one relaxed default bound, only one is supported
-  --> $DIR/bad-suggestionf-for-repeated-unsized-bound-127441.rs:35:17
+error[E0203]: duplicate relaxed `Sized` bounds
+  --> $DIR/fix-dyn-sized-fn-param-sugg.rs:34:17
    |
 LL | fn foo8(_: impl ?Sized + Debug + ?Sized ) {}
    |                 ^^^^^^           ^^^^^^
 
 error[E0277]: the size for values of type `T` cannot be known at compilation time
-  --> $DIR/bad-suggestionf-for-repeated-unsized-bound-127441.rs:9:23
+  --> $DIR/fix-dyn-sized-fn-param-sugg.rs:8:23
    |
 LL | fn foo1<T: ?Sized>(a: T) {}
    |         -             ^ doesn't have a size known at compile-time
@@ -54,7 +54,7 @@ LL | fn foo1<T: ?Sized>(a: &T) {}
    |                       +
 
 error[E0277]: the size for values of type `T` cannot be known at compilation time
-  --> $DIR/bad-suggestionf-for-repeated-unsized-bound-127441.rs:12:32
+  --> $DIR/fix-dyn-sized-fn-param-sugg.rs:11:32
    |
 LL | fn foo2<T: ?Sized + ?Sized>(a: T) {}
    |         -                      ^ doesn't have a size known at compile-time
@@ -73,7 +73,7 @@ LL | fn foo2<T: ?Sized + ?Sized>(a: &T) {}
    |                                +
 
 error[E0277]: the size for values of type `T` cannot be known at compilation time
-  --> $DIR/bad-suggestionf-for-repeated-unsized-bound-127441.rs:16:40
+  --> $DIR/fix-dyn-sized-fn-param-sugg.rs:15:40
    |
 LL | fn foo3<T: ?Sized + ?Sized + Debug>(a: T) {}
    |         -                              ^ doesn't have a size known at compile-time
@@ -92,7 +92,7 @@ LL | fn foo3<T: ?Sized + ?Sized + Debug>(a: &T) {}
    |                                        +
 
 error[E0277]: the size for values of type `T` cannot be known at compilation time
-  --> $DIR/bad-suggestionf-for-repeated-unsized-bound-127441.rs:20:41
+  --> $DIR/fix-dyn-sized-fn-param-sugg.rs:19:41
    |
 LL | fn foo4<T: ?Sized + Debug + ?Sized >(a: T) {}
    |         -                               ^ doesn't have a size known at compile-time
@@ -111,7 +111,7 @@ LL | fn foo4<T: ?Sized + Debug + ?Sized >(a: &T) {}
    |                                         +
 
 error[E0277]: the size for values of type `impl ?Sized` cannot be known at compilation time
-  --> $DIR/bad-suggestionf-for-repeated-unsized-bound-127441.rs:24:12
+  --> $DIR/fix-dyn-sized-fn-param-sugg.rs:23:12
    |
 LL | fn foo5(_: impl ?Sized) {}
    |            ^^^^^^^^^^^
@@ -131,7 +131,7 @@ LL | fn foo5(_: &impl ?Sized) {}
    |            +
 
 error[E0277]: the size for values of type `impl ?Sized + ?Sized` cannot be known at compilation time
-  --> $DIR/bad-suggestionf-for-repeated-unsized-bound-127441.rs:27:12
+  --> $DIR/fix-dyn-sized-fn-param-sugg.rs:26:12
    |
 LL | fn foo6(_: impl ?Sized + ?Sized) {}
    |            ^^^^^^^^^^^^^^^^^^^^
@@ -151,7 +151,7 @@ LL | fn foo6(_: &impl ?Sized + ?Sized) {}
    |            +
 
 error[E0277]: the size for values of type `impl ?Sized + ?Sized + Debug` cannot be known at compilation time
-  --> $DIR/bad-suggestionf-for-repeated-unsized-bound-127441.rs:31:12
+  --> $DIR/fix-dyn-sized-fn-param-sugg.rs:30:12
    |
 LL | fn foo7(_: impl ?Sized + ?Sized + Debug) {}
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -171,7 +171,7 @@ LL | fn foo7(_: &impl ?Sized + ?Sized + Debug) {}
    |            +
 
 error[E0277]: the size for values of type `impl ?Sized + Debug + ?Sized` cannot be known at compilation time
-  --> $DIR/bad-suggestionf-for-repeated-unsized-bound-127441.rs:35:12
+  --> $DIR/fix-dyn-sized-fn-param-sugg.rs:34:12
    |
 LL | fn foo8(_: impl ?Sized + Debug + ?Sized ) {}
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/trait-bounds/more_maybe_bounds.rs b/tests/ui/trait-bounds/more_maybe_bounds.rs
index 61b630479ac..47348b0a0dd 100644
--- a/tests/ui/trait-bounds/more_maybe_bounds.rs
+++ b/tests/ui/trait-bounds/more_maybe_bounds.rs
@@ -1,6 +1,6 @@
 // FIXME(more_maybe_bounds): Even under `more_maybe_bounds` / `-Zexperimental-default-bounds`,
 // trying to relax non-default bounds should still be an error in all contexts! As you can see
-// there are placed like supertrait bounds and trait object types where we currently don't perform
+// there are places like supertrait bounds and trait object types where we currently don't perform
 // this check.
 #![feature(auto_traits, more_maybe_bounds, negative_impls)]
 
diff --git a/tests/ui/traits/maybe-polarity-repeated.rs b/tests/ui/traits/maybe-polarity-repeated.rs
deleted file mode 100644
index 962e3d5dbc5..00000000000
--- a/tests/ui/traits/maybe-polarity-repeated.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-#![feature(more_maybe_bounds)]
-
-trait Trait {}
-fn foo<T: ?Trait + ?Trait>(_: T) {}
-//~^ ERROR type parameter has more than one relaxed default bound, only one is supported
-//~| ERROR bound modifier `?` can only be applied to default traits like `Sized`
-//~| ERROR bound modifier `?` can only be applied to default traits like `Sized`
-
-fn main() {}
diff --git a/tests/ui/traits/maybe-polarity-repeated.stderr b/tests/ui/traits/maybe-polarity-repeated.stderr
deleted file mode 100644
index de16c147180..00000000000
--- a/tests/ui/traits/maybe-polarity-repeated.stderr
+++ /dev/null
@@ -1,21 +0,0 @@
-error[E0203]: type parameter has more than one relaxed default bound, only one is supported
-  --> $DIR/maybe-polarity-repeated.rs:4:11
-   |
-LL | fn foo<T: ?Trait + ?Trait>(_: T) {}
-   |           ^^^^^^   ^^^^^^
-
-error: bound modifier `?` can only be applied to default traits like `Sized`
-  --> $DIR/maybe-polarity-repeated.rs:4:11
-   |
-LL | fn foo<T: ?Trait + ?Trait>(_: T) {}
-   |           ^^^^^^
-
-error: bound modifier `?` can only be applied to default traits like `Sized`
-  --> $DIR/maybe-polarity-repeated.rs:4:20
-   |
-LL | fn foo<T: ?Trait + ?Trait>(_: T) {}
-   |                    ^^^^^^
-
-error: aborting due to 3 previous errors
-
-For more information about this error, try `rustc --explain E0203`.
diff --git a/tests/ui/unsized/relaxed-bounds-invalid-places.rs b/tests/ui/unsized/relaxed-bounds-invalid-places.rs
index 64d4523ac49..b8eda1e7786 100644
--- a/tests/ui/unsized/relaxed-bounds-invalid-places.rs
+++ b/tests/ui/unsized/relaxed-bounds-invalid-places.rs
@@ -16,8 +16,7 @@ struct S4<T>(T) where for<'a> T: ?Trait<'a>;
 //~| ERROR bound modifier `?` can only be applied to `Sized`
 
 struct S5<T>(*const T) where T: ?Trait<'static> + ?Sized;
-//~^ ERROR type parameter has more than one relaxed default bound
-//~| ERROR bound modifier `?` can only be applied to `Sized`
+//~^ ERROR bound modifier `?` can only be applied to `Sized`
 
 impl<T> S1<T> {
     fn f() where T: ?Sized {} //~ ERROR this relaxed bound is not permitted here
@@ -33,4 +32,3 @@ type O2 = dyn ?Sized + ?Sized + Tr;
 //~| ERROR relaxed bounds are not permitted in trait object types
 
 fn main() {}
-
diff --git a/tests/ui/unsized/relaxed-bounds-invalid-places.stderr b/tests/ui/unsized/relaxed-bounds-invalid-places.stderr
index cfa0d274b26..30285d62693 100644
--- a/tests/ui/unsized/relaxed-bounds-invalid-places.stderr
+++ b/tests/ui/unsized/relaxed-bounds-invalid-places.stderr
@@ -31,7 +31,7 @@ LL | struct S4<T>(T) where for<'a> T: ?Trait<'a>;
    = note: in this context, relaxed bounds are only allowed on type parameters defined by the closest item
 
 error: this relaxed bound is not permitted here
-  --> $DIR/relaxed-bounds-invalid-places.rs:23:21
+  --> $DIR/relaxed-bounds-invalid-places.rs:22:21
    |
 LL |     fn f() where T: ?Sized {}
    |                     ^^^^^^
@@ -39,7 +39,7 @@ LL |     fn f() where T: ?Sized {}
    = note: in this context, relaxed bounds are only allowed on type parameters defined by the closest item
 
 error: relaxed bounds are not permitted in supertrait bounds
-  --> $DIR/relaxed-bounds-invalid-places.rs:26:11
+  --> $DIR/relaxed-bounds-invalid-places.rs:25:11
    |
 LL | trait Tr: ?Sized {}
    |           ^^^^^^
@@ -47,19 +47,19 @@ LL | trait Tr: ?Sized {}
    = note: traits are `?Sized` by default
 
 error: relaxed bounds are not permitted in trait object types
-  --> $DIR/relaxed-bounds-invalid-places.rs:30:20
+  --> $DIR/relaxed-bounds-invalid-places.rs:29:20
    |
 LL | type O1 = dyn Tr + ?Sized;
    |                    ^^^^^^
 
 error: relaxed bounds are not permitted in trait object types
-  --> $DIR/relaxed-bounds-invalid-places.rs:31:15
+  --> $DIR/relaxed-bounds-invalid-places.rs:30:15
    |
 LL | type O2 = dyn ?Sized + ?Sized + Tr;
    |               ^^^^^^
 
 error: relaxed bounds are not permitted in trait object types
-  --> $DIR/relaxed-bounds-invalid-places.rs:31:24
+  --> $DIR/relaxed-bounds-invalid-places.rs:30:24
    |
 LL | type O2 = dyn ?Sized + ?Sized + Tr;
    |                        ^^^^^^
@@ -70,21 +70,11 @@ error: bound modifier `?` can only be applied to `Sized`
 LL | struct S4<T>(T) where for<'a> T: ?Trait<'a>;
    |                                  ^^^^^^^^^^
 
-error[E0203]: type parameter has more than one relaxed default bound, only one is supported
-  --> $DIR/relaxed-bounds-invalid-places.rs:18:33
-   |
-LL | struct S5<T>(*const T) where T: ?Trait<'static> + ?Sized;
-   |                                 ^^^^^^^^^^^^^^^   ^^^^^^
-   |
-   = help: add `#![feature(more_maybe_bounds)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-
 error: bound modifier `?` can only be applied to `Sized`
   --> $DIR/relaxed-bounds-invalid-places.rs:18:33
    |
 LL | struct S5<T>(*const T) where T: ?Trait<'static> + ?Sized;
    |                                 ^^^^^^^^^^^^^^^
 
-error: aborting due to 12 previous errors
+error: aborting due to 11 previous errors
 
-For more information about this error, try `rustc --explain E0203`.