Auto merge of #77224 - RalfJung:rollup-hdvb96c, r=RalfJung

Rollup of 12 pull requests

Successful merges:

 - #75454 (Explicitly document the size guarantees that Option makes.)
 - #76631 (Add `x.py setup`)
 - #77076 (Add missing code examples on slice iter types)
 - #77093 (merge `need_type_info_err(_const)`)
 - #77122 (Add `#![feature(const_fn_floating_point_arithmetic)]`)
 - #77127 (Update mdBook)
 - #77161 (Remove TrustedLen requirement from BuilderMethods::switch)
 - #77166 (update Miri)
 - #77181 (Add doc alias for pointer primitive)
 - #77204 (Remove stray word from `ClosureKind::extends` docs)
 - #77207 (Rename `whence` to `span`)
 - #77211 (Remove unused #[allow(...)] statements from compiler/)

Failed merges:

 - #77170 (Remove `#[rustc_allow_const_fn_ptr]` and add `#![feature(const_fn_fn_ptr_basics)]`)

r? `@ghost`

20 files changed, 138 insertions, 93 deletions

diff --git a/src/test/ui/const-generics/infer/cannot-infer-const-args.full.stderr b/src/test/ui/const-generics/infer/cannot-infer-const-args.full.stderr
index 84e75cc3764..b438ed3ad65 100644
--- a/src/test/ui/const-generics/infer/cannot-infer-const-args.full.stderr
+++ b/src/test/ui/const-generics/infer/cannot-infer-const-args.full.stderr
@@ -2,9 +2,7 @@ error[E0282]: type annotations needed
   --> $DIR/cannot-infer-const-args.rs:12:5
    |
 LL |     foo();
-   |     ^^^
-   |
-   = note: cannot infer the value of the const parameter `X`
+   |     ^^^ cannot infer the value of const parameter `X` declared on the function `foo`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/infer/cannot-infer-const-args.min.stderr b/src/test/ui/const-generics/infer/cannot-infer-const-args.min.stderr
index 84e75cc3764..b438ed3ad65 100644
--- a/src/test/ui/const-generics/infer/cannot-infer-const-args.min.stderr
+++ b/src/test/ui/const-generics/infer/cannot-infer-const-args.min.stderr
@@ -2,9 +2,7 @@ error[E0282]: type annotations needed
   --> $DIR/cannot-infer-const-args.rs:12:5
    |
 LL |     foo();
-   |     ^^^
-   |
-   = note: cannot infer the value of the const parameter `X`
+   |     ^^^ cannot infer the value of const parameter `X` declared on the function `foo`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/infer/issue-77092.rs b/src/test/ui/const-generics/infer/issue-77092.rs
new file mode 100644
index 00000000000..9a1dd1a8258
--- /dev/null
+++ b/src/test/ui/const-generics/infer/issue-77092.rs
@@ -0,0 +1,16 @@
+#![feature(min_const_generics)]
+
+use std::convert::TryInto;
+
+fn take_array_from_mut<T, const N: usize>(data: &mut [T], start: usize) -> &mut [T; N] {
+    (&mut data[start .. start + N]).try_into().unwrap()
+}
+
+fn main() {
+    let mut arr = [0, 1, 2, 3, 4, 5, 6, 7, 8];
+
+    for i in 1 .. 4 {
+        println!("{:?}", take_array_from_mut(&mut arr, i));
+        //~^ ERROR type annotations needed
+    }
+}
diff --git a/src/test/ui/const-generics/infer/issue-77092.stderr b/src/test/ui/const-generics/infer/issue-77092.stderr
new file mode 100644
index 00000000000..e84ff8baeea
--- /dev/null
+++ b/src/test/ui/const-generics/infer/issue-77092.stderr
@@ -0,0 +1,9 @@
+error[E0282]: type annotations needed
+  --> $DIR/issue-77092.rs:13:26
+   |
+LL |         println!("{:?}", take_array_from_mut(&mut arr, i));
+   |                          ^^^^^^^^^^^^^^^^^^^ cannot infer the value of the constant `{_: usize}`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0282`.
diff --git a/src/test/ui/const-generics/infer/method-chain.full.stderr b/src/test/ui/const-generics/infer/method-chain.full.stderr
index e65bc3f1096..1fb0b23cf11 100644
--- a/src/test/ui/const-generics/infer/method-chain.full.stderr
+++ b/src/test/ui/const-generics/infer/method-chain.full.stderr
@@ -2,9 +2,7 @@ error[E0282]: type annotations needed
   --> $DIR/method-chain.rs:21:33
    |
 LL |     Foo.bar().bar().bar().bar().baz();
-   |                                 ^^^
-   |
-   = note: cannot infer the value of the const parameter `N`
+   |                                 ^^^ cannot infer the value of const parameter `N` declared on the associated function `baz`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/infer/method-chain.min.stderr b/src/test/ui/const-generics/infer/method-chain.min.stderr
index e65bc3f1096..1fb0b23cf11 100644
--- a/src/test/ui/const-generics/infer/method-chain.min.stderr
+++ b/src/test/ui/const-generics/infer/method-chain.min.stderr
@@ -2,9 +2,7 @@ error[E0282]: type annotations needed
   --> $DIR/method-chain.rs:21:33
    |
 LL |     Foo.bar().bar().bar().bar().baz();
-   |                                 ^^^
-   |
-   = note: cannot infer the value of the const parameter `N`
+   |                                 ^^^ cannot infer the value of const parameter `N` declared on the associated function `baz`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/infer/uninferred-consts.full.stderr b/src/test/ui/const-generics/infer/uninferred-consts.full.stderr
index e47b6bd5dc6..7a451903e96 100644
--- a/src/test/ui/const-generics/infer/uninferred-consts.full.stderr
+++ b/src/test/ui/const-generics/infer/uninferred-consts.full.stderr
@@ -2,9 +2,7 @@ error[E0282]: type annotations needed
   --> $DIR/uninferred-consts.rs:14:9
    |
 LL |     Foo.foo();
-   |         ^^^
-   |
-   = note: cannot infer the value of the const parameter `N`
+   |         ^^^ cannot infer the value of const parameter `N` declared on the associated function `foo`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/infer/uninferred-consts.min.stderr b/src/test/ui/const-generics/infer/uninferred-consts.min.stderr
index e47b6bd5dc6..7a451903e96 100644
--- a/src/test/ui/const-generics/infer/uninferred-consts.min.stderr
+++ b/src/test/ui/const-generics/infer/uninferred-consts.min.stderr
@@ -2,9 +2,7 @@ error[E0282]: type annotations needed
   --> $DIR/uninferred-consts.rs:14:9
    |
 LL |     Foo.foo();
-   |         ^^^
-   |
-   = note: cannot infer the value of the const parameter `N`
+   |         ^^^ cannot infer the value of const parameter `N` declared on the associated function `foo`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/consts/const-extern-fn/const-extern-fn-min-const-fn.rs b/src/test/ui/consts/const-extern-fn/const-extern-fn-min-const-fn.rs
index e0b9e5f3375..094ae7378bc 100644
--- a/src/test/ui/consts/const-extern-fn/const-extern-fn-min-const-fn.rs
+++ b/src/test/ui/consts/const-extern-fn/const-extern-fn-min-const-fn.rs
@@ -4,7 +4,7 @@ const extern fn unsize(x: &[u8; 3]) -> &[u8] { x }
 const unsafe extern "C" fn closure() -> fn() { || {} }
 //~^ ERROR function pointers in const fn are unstable
 const unsafe extern fn use_float() { 1.0 + 1.0; }
-//~^ ERROR only int, `bool` and `char` operations are stable in const fn
+//~^ ERROR floating point arithmetic
 const extern "C" fn ptr_cast(val: *const u8) { val as usize; }
 //~^ ERROR casting pointers to integers
 
diff --git a/src/test/ui/consts/const-extern-fn/const-extern-fn-min-const-fn.stderr b/src/test/ui/consts/const-extern-fn/const-extern-fn-min-const-fn.stderr
index 5ca44b3fa7e..fcc34f358f9 100644
--- a/src/test/ui/consts/const-extern-fn/const-extern-fn-min-const-fn.stderr
+++ b/src/test/ui/consts/const-extern-fn/const-extern-fn-min-const-fn.stderr
@@ -7,14 +7,14 @@ LL | const unsafe extern "C" fn closure() -> fn() { || {} }
    = note: see issue #57563 <https://github.com/rust-lang/rust/issues/57563> for more information
    = help: add `#![feature(const_fn)]` to the crate attributes to enable
 
-error[E0723]: only int, `bool` and `char` operations are stable in const fn
+error[E0658]: floating point arithmetic is not allowed in constant functions
   --> $DIR/const-extern-fn-min-const-fn.rs:6:38
    |
 LL | const unsafe extern fn use_float() { 1.0 + 1.0; }
    |                                      ^^^^^^^^^
    |
-   = note: see issue #57563 <https://github.com/rust-lang/rust/issues/57563> for more information
-   = help: add `#![feature(const_fn)]` to the crate attributes to enable
+   = note: see issue #57241 <https://github.com/rust-lang/rust/issues/57241> for more information
+   = help: add `#![feature(const_fn_floating_point_arithmetic)]` to the crate attributes to enable
 
 error[E0658]: casting pointers to integers in constant functions is unstable
   --> $DIR/const-extern-fn-min-const-fn.rs:8:48
diff --git a/src/test/ui/consts/const_fn_floating_point_arithmetic.gated.stderr b/src/test/ui/consts/const_fn_floating_point_arithmetic.gated.stderr
new file mode 100644
index 00000000000..ae24f8f6500
--- /dev/null
+++ b/src/test/ui/consts/const_fn_floating_point_arithmetic.gated.stderr
@@ -0,0 +1,8 @@
+error: fatal error triggered by #[rustc_error]
+  --> $DIR/const_fn_floating_point_arithmetic.rs:20:1
+   |
+LL | fn main() {}
+   | ^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/consts/const_fn_floating_point_arithmetic.rs b/src/test/ui/consts/const_fn_floating_point_arithmetic.rs
new file mode 100644
index 00000000000..5e32482b21a
--- /dev/null
+++ b/src/test/ui/consts/const_fn_floating_point_arithmetic.rs
@@ -0,0 +1,20 @@
+// gate-test-const_fn_floating_point_arithmetic
+
+// revisions: stock gated
+
+#![feature(rustc_attrs)]
+#![cfg_attr(gated, feature(const_fn_floating_point_arithmetic))]
+
+const fn add(f: f32) -> f32 { f + 2.0 }
+//[stock]~^ floating point arithmetic
+const fn sub(f: f32) -> f32 { 2.0 - f }
+//[stock]~^ floating point arithmetic
+const fn mul(f: f32, g: f32) -> f32 { f * g }
+//[stock]~^ floating point arithmetic
+const fn div(f: f32, g: f32) -> f32 { f / g }
+//[stock]~^ floating point arithmetic
+const fn neg(f: f32) -> f32 { -f }
+//[stock]~^ floating point arithmetic
+
+#[rustc_error]
+fn main() {} //[gated]~ fatal error triggered by #[rustc_error]
diff --git a/src/test/ui/consts/const_fn_floating_point_arithmetic.stock.stderr b/src/test/ui/consts/const_fn_floating_point_arithmetic.stock.stderr
new file mode 100644
index 00000000000..ef7a60faf3f
--- /dev/null
+++ b/src/test/ui/consts/const_fn_floating_point_arithmetic.stock.stderr
@@ -0,0 +1,48 @@
+error[E0658]: floating point arithmetic is not allowed in constant functions
+  --> $DIR/const_fn_floating_point_arithmetic.rs:8:31
+   |
+LL | const fn add(f: f32) -> f32 { f + 2.0 }
+   |                               ^^^^^^^
+   |
+   = note: see issue #57241 <https://github.com/rust-lang/rust/issues/57241> for more information
+   = help: add `#![feature(const_fn_floating_point_arithmetic)]` to the crate attributes to enable
+
+error[E0658]: floating point arithmetic is not allowed in constant functions
+  --> $DIR/const_fn_floating_point_arithmetic.rs:10:31
+   |
+LL | const fn sub(f: f32) -> f32 { 2.0 - f }
+   |                               ^^^^^^^
+   |
+   = note: see issue #57241 <https://github.com/rust-lang/rust/issues/57241> for more information
+   = help: add `#![feature(const_fn_floating_point_arithmetic)]` to the crate attributes to enable
+
+error[E0658]: floating point arithmetic is not allowed in constant functions
+  --> $DIR/const_fn_floating_point_arithmetic.rs:12:39
+   |
+LL | const fn mul(f: f32, g: f32) -> f32 { f * g }
+   |                                       ^^^^^
+   |
+   = note: see issue #57241 <https://github.com/rust-lang/rust/issues/57241> for more information
+   = help: add `#![feature(const_fn_floating_point_arithmetic)]` to the crate attributes to enable
+
+error[E0658]: floating point arithmetic is not allowed in constant functions
+  --> $DIR/const_fn_floating_point_arithmetic.rs:14:39
+   |
+LL | const fn div(f: f32, g: f32) -> f32 { f / g }
+   |                                       ^^^^^
+   |
+   = note: see issue #57241 <https://github.com/rust-lang/rust/issues/57241> for more information
+   = help: add `#![feature(const_fn_floating_point_arithmetic)]` to the crate attributes to enable
+
+error[E0658]: floating point arithmetic is not allowed in constant functions
+  --> $DIR/const_fn_floating_point_arithmetic.rs:16:31
+   |
+LL | const fn neg(f: f32) -> f32 { -f }
+   |                               ^^
+   |
+   = note: see issue #57241 <https://github.com/rust-lang/rust/issues/57241> for more information
+   = help: add `#![feature(const_fn_floating_point_arithmetic)]` to the crate attributes to enable
+
+error: aborting due to 5 previous errors
+
+For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/consts/const_let_eq_float.rs b/src/test/ui/consts/const_let_eq_float.rs
index bc0ef26eb2f..e15f4b804f7 100644
--- a/src/test/ui/consts/const_let_eq_float.rs
+++ b/src/test/ui/consts/const_let_eq_float.rs
@@ -1,6 +1,6 @@
-// build-pass (FIXME(62277): could be check-pass?)
+// run-pass
 
-#![feature(const_fn)]
+#![feature(const_fn_floating_point_arithmetic)]
 
 struct Foo<T>(T);
 struct Bar<T> { x: T }
diff --git a/src/test/ui/consts/min_const_fn/min_const_fn.rs b/src/test/ui/consts/min_const_fn/min_const_fn.rs
index 336d754b06a..55a999d5cdc 100644
--- a/src/test/ui/consts/min_const_fn/min_const_fn.rs
+++ b/src/test/ui/consts/min_const_fn/min_const_fn.rs
@@ -77,14 +77,6 @@ const fn foo11<T: std::fmt::Display>(t: T) -> T { t }
 //~^ ERROR trait bounds other than `Sized` on const fn parameters are unstable
 const fn foo11_2<T: Send>(t: T) -> T { t }
 //~^ ERROR trait bounds other than `Sized` on const fn parameters are unstable
-const fn foo19(f: f32) -> f32 { f * 2.0 }
-//~^ ERROR int, `bool` and `char` operations
-const fn foo19_2(f: f32) -> f32 { 2.0 - f }
-//~^ ERROR int, `bool` and `char` operations
-const fn foo19_3(f: f32) -> f32 { -f }
-//~^ ERROR int, `bool` and `char` operations
-const fn foo19_4(f: f32, g: f32) -> f32 { f / g }
-//~^ ERROR int, `bool` and `char` operations
 
 static BAR: u32 = 42;
 const fn foo25() -> u32 { BAR } //~ ERROR cannot refer to statics
diff --git a/src/test/ui/consts/min_const_fn/min_const_fn.stderr b/src/test/ui/consts/min_const_fn/min_const_fn.stderr
index c96500e38ec..a37e5203eee 100644
--- a/src/test/ui/consts/min_const_fn/min_const_fn.stderr
+++ b/src/test/ui/consts/min_const_fn/min_const_fn.stderr
@@ -76,44 +76,8 @@ LL | const fn foo11_2<T: Send>(t: T) -> T { t }
    = note: see issue #57563 <https://github.com/rust-lang/rust/issues/57563> for more information
    = help: add `#![feature(const_fn)]` to the crate attributes to enable
 
-error[E0723]: only int, `bool` and `char` operations are stable in const fn
-  --> $DIR/min_const_fn.rs:80:33
-   |
-LL | const fn foo19(f: f32) -> f32 { f * 2.0 }
-   |                                 ^^^^^^^
-   |
-   = note: see issue #57563 <https://github.com/rust-lang/rust/issues/57563> for more information
-   = help: add `#![feature(const_fn)]` to the crate attributes to enable
-
-error[E0723]: only int, `bool` and `char` operations are stable in const fn
-  --> $DIR/min_const_fn.rs:82:35
-   |
-LL | const fn foo19_2(f: f32) -> f32 { 2.0 - f }
-   |                                   ^^^^^^^
-   |
-   = note: see issue #57563 <https://github.com/rust-lang/rust/issues/57563> for more information
-   = help: add `#![feature(const_fn)]` to the crate attributes to enable
-
-error[E0723]: only int, `bool` and `char` operations are stable in const fn
-  --> $DIR/min_const_fn.rs:84:35
-   |
-LL | const fn foo19_3(f: f32) -> f32 { -f }
-   |                                   ^^
-   |
-   = note: see issue #57563 <https://github.com/rust-lang/rust/issues/57563> for more information
-   = help: add `#![feature(const_fn)]` to the crate attributes to enable
-
-error[E0723]: only int, `bool` and `char` operations are stable in const fn
-  --> $DIR/min_const_fn.rs:86:43
-   |
-LL | const fn foo19_4(f: f32, g: f32) -> f32 { f / g }
-   |                                           ^^^^^
-   |
-   = note: see issue #57563 <https://github.com/rust-lang/rust/issues/57563> for more information
-   = help: add `#![feature(const_fn)]` to the crate attributes to enable
-
 error[E0013]: constant functions cannot refer to statics
-  --> $DIR/min_const_fn.rs:90:27
+  --> $DIR/min_const_fn.rs:82:27
    |
 LL | const fn foo25() -> u32 { BAR }
    |                           ^^^
@@ -121,7 +85,7 @@ LL | const fn foo25() -> u32 { BAR }
    = help: consider extracting the value of the `static` to a `const`, and referring to that
 
 error[E0013]: constant functions cannot refer to statics
-  --> $DIR/min_const_fn.rs:91:37
+  --> $DIR/min_const_fn.rs:83:37
    |
 LL | const fn foo26() -> &'static u32 { &BAR }
    |                                     ^^^
@@ -129,7 +93,7 @@ LL | const fn foo26() -> &'static u32 { &BAR }
    = help: consider extracting the value of the `static` to a `const`, and referring to that
 
 error[E0658]: casting pointers to integers in constant functions is unstable
-  --> $DIR/min_const_fn.rs:92:42
+  --> $DIR/min_const_fn.rs:84:42
    |
 LL | const fn foo30(x: *const u32) -> usize { x as usize }
    |                                          ^^^^^^^^^^
@@ -138,7 +102,7 @@ LL | const fn foo30(x: *const u32) -> usize { x as usize }
    = help: add `#![feature(const_raw_ptr_to_usize_cast)]` to the crate attributes to enable
 
 error[E0658]: casting pointers to integers in constant functions is unstable
-  --> $DIR/min_const_fn.rs:94:63
+  --> $DIR/min_const_fn.rs:86:63
    |
 LL | const fn foo30_with_unsafe(x: *const u32) -> usize { unsafe { x as usize } }
    |                                                               ^^^^^^^^^^
@@ -147,7 +111,7 @@ LL | const fn foo30_with_unsafe(x: *const u32) -> usize { unsafe { x as usize }
    = help: add `#![feature(const_raw_ptr_to_usize_cast)]` to the crate attributes to enable
 
 error[E0658]: casting pointers to integers in constant functions is unstable
-  --> $DIR/min_const_fn.rs:96:42
+  --> $DIR/min_const_fn.rs:88:42
    |
 LL | const fn foo30_2(x: *mut u32) -> usize { x as usize }
    |                                          ^^^^^^^^^^
@@ -156,7 +120,7 @@ LL | const fn foo30_2(x: *mut u32) -> usize { x as usize }
    = help: add `#![feature(const_raw_ptr_to_usize_cast)]` to the crate attributes to enable
 
 error[E0658]: casting pointers to integers in constant functions is unstable
-  --> $DIR/min_const_fn.rs:98:63
+  --> $DIR/min_const_fn.rs:90:63
    |
 LL | const fn foo30_2_with_unsafe(x: *mut u32) -> usize { unsafe { x as usize } }
    |                                                               ^^^^^^^^^^
@@ -165,7 +129,7 @@ LL | const fn foo30_2_with_unsafe(x: *mut u32) -> usize { unsafe { x as usize }
    = help: add `#![feature(const_raw_ptr_to_usize_cast)]` to the crate attributes to enable
 
 error[E0658]: mutable references are not allowed in constant functions
-  --> $DIR/min_const_fn.rs:101:14
+  --> $DIR/min_const_fn.rs:93:14
    |
 LL | const fn inc(x: &mut i32) { *x += 1 }
    |              ^
@@ -174,7 +138,7 @@ LL | const fn inc(x: &mut i32) { *x += 1 }
    = help: add `#![feature(const_mut_refs)]` to the crate attributes to enable
 
 error[E0723]: trait bounds other than `Sized` on const fn parameters are unstable
-  --> $DIR/min_const_fn.rs:110:6
+  --> $DIR/min_const_fn.rs:102:6
    |
 LL | impl<T: std::fmt::Debug> Foo<T> {
    |      ^
@@ -183,7 +147,7 @@ LL | impl<T: std::fmt::Debug> Foo<T> {
    = help: add `#![feature(const_fn)]` to the crate attributes to enable
 
 error[E0723]: trait bounds other than `Sized` on const fn parameters are unstable
-  --> $DIR/min_const_fn.rs:115:6
+  --> $DIR/min_const_fn.rs:107:6
    |
 LL | impl<T: std::fmt::Debug + Sized> Foo<T> {
    |      ^
@@ -192,7 +156,7 @@ LL | impl<T: std::fmt::Debug + Sized> Foo<T> {
    = help: add `#![feature(const_fn)]` to the crate attributes to enable
 
 error[E0723]: trait bounds other than `Sized` on const fn parameters are unstable
-  --> $DIR/min_const_fn.rs:120:6
+  --> $DIR/min_const_fn.rs:112:6
    |
 LL | impl<T: Sync + Sized> Foo<T> {
    |      ^
@@ -201,7 +165,7 @@ LL | impl<T: Sync + Sized> Foo<T> {
    = help: add `#![feature(const_fn)]` to the crate attributes to enable
 
 error[E0723]: trait bounds other than `Sized` on const fn parameters are unstable
-  --> $DIR/min_const_fn.rs:126:34
+  --> $DIR/min_const_fn.rs:118:34
    |
 LL | const fn no_apit2(_x: AlanTuring<impl std::fmt::Debug>) {}
    |                                  ^^^^^^^^^^^^^^^^^^^^
@@ -210,7 +174,7 @@ LL | const fn no_apit2(_x: AlanTuring<impl std::fmt::Debug>) {}
    = help: add `#![feature(const_fn)]` to the crate attributes to enable
 
 error[E0723]: trait bounds other than `Sized` on const fn parameters are unstable
-  --> $DIR/min_const_fn.rs:128:22
+  --> $DIR/min_const_fn.rs:120:22
    |
 LL | const fn no_apit(_x: impl std::fmt::Debug) {}
    |                      ^^^^^^^^^^^^^^^^^^^^
@@ -219,7 +183,7 @@ LL | const fn no_apit(_x: impl std::fmt::Debug) {}
    = help: add `#![feature(const_fn)]` to the crate attributes to enable
 
 error[E0723]: trait bounds other than `Sized` on const fn parameters are unstable
-  --> $DIR/min_const_fn.rs:129:23
+  --> $DIR/min_const_fn.rs:121:23
    |
 LL | const fn no_dyn_trait(_x: &dyn std::fmt::Debug) {}
    |                       ^^
@@ -228,7 +192,7 @@ LL | const fn no_dyn_trait(_x: &dyn std::fmt::Debug) {}
    = help: add `#![feature(const_fn)]` to the crate attributes to enable
 
 error[E0723]: trait bounds other than `Sized` on const fn parameters are unstable
-  --> $DIR/min_const_fn.rs:130:32
+  --> $DIR/min_const_fn.rs:122:32
    |
 LL | const fn no_dyn_trait_ret() -> &'static dyn std::fmt::Debug { &() }
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -237,7 +201,7 @@ LL | const fn no_dyn_trait_ret() -> &'static dyn std::fmt::Debug { &() }
    = help: add `#![feature(const_fn)]` to the crate attributes to enable
 
 error[E0723]: trait bounds other than `Sized` on const fn parameters are unstable
-  --> $DIR/min_const_fn.rs:135:41
+  --> $DIR/min_const_fn.rs:127:41
    |
 LL | const fn really_no_traits_i_mean_it() { (&() as &dyn std::fmt::Debug, ()).1 }
    |                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -246,7 +210,7 @@ LL | const fn really_no_traits_i_mean_it() { (&() as &dyn std::fmt::Debug, ()).1
    = help: add `#![feature(const_fn)]` to the crate attributes to enable
 
 error[E0723]: function pointers in const fn are unstable
-  --> $DIR/min_const_fn.rs:138:21
+  --> $DIR/min_const_fn.rs:130:21
    |
 LL | const fn no_fn_ptrs(_x: fn()) {}
    |                     ^^
@@ -255,7 +219,7 @@ LL | const fn no_fn_ptrs(_x: fn()) {}
    = help: add `#![feature(const_fn)]` to the crate attributes to enable
 
 error[E0723]: function pointers in const fn are unstable
-  --> $DIR/min_const_fn.rs:140:27
+  --> $DIR/min_const_fn.rs:132:27
    |
 LL | const fn no_fn_ptrs2() -> fn() { fn foo() {} foo }
    |                           ^^^^
@@ -263,7 +227,7 @@ LL | const fn no_fn_ptrs2() -> fn() { fn foo() {} foo }
    = note: see issue #57563 <https://github.com/rust-lang/rust/issues/57563> for more information
    = help: add `#![feature(const_fn)]` to the crate attributes to enable
 
-error: aborting due to 30 previous errors
+error: aborting due to 26 previous errors
 
 Some errors have detailed explanations: E0013, E0493, E0658, E0723.
 For more information about an error, try `rustc --explain E0013`.
diff --git a/src/test/ui/consts/min_const_fn/min_const_fn_libstd_stability.rs b/src/test/ui/consts/min_const_fn/min_const_fn_libstd_stability.rs
index b83fdf7c656..292e2dd167c 100644
--- a/src/test/ui/consts/min_const_fn/min_const_fn_libstd_stability.rs
+++ b/src/test/ui/consts/min_const_fn/min_const_fn_libstd_stability.rs
@@ -3,7 +3,7 @@
             we're apparently really bad at it",
             issue = "none")]
 
-#![feature(const_fn, foo, foo2)]
+#![feature(const_fn, const_fn_floating_point_arithmetic, foo, foo2)]
 #![feature(staged_api)]
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -25,9 +25,9 @@ const fn bar2() -> u32 { foo2() } //~ ERROR not yet stable as a const fn
 
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_const_stable(feature = "rust1", since = "1.0.0")]
-// conformity is required, even with `const_fn` feature gate
+// Const-stable functions cannot rely on unstable const-eval features.
 const fn bar3() -> u32 { (5f32 + 6f32) as u32 }
-//~^ ERROR const-stable function cannot use `#[feature(const_fn)]`
+//~^ ERROR const-stable function cannot use `#[feature(const_fn_floating_point_arithmetic)]`
 
 // check whether this function cannot be called even with the feature gate active
 #[unstable(feature = "foo2", issue = "none")]
diff --git a/src/test/ui/consts/min_const_fn/min_const_fn_libstd_stability.stderr b/src/test/ui/consts/min_const_fn/min_const_fn_libstd_stability.stderr
index a1f1f6f52ab..fa2260b40d1 100644
--- a/src/test/ui/consts/min_const_fn/min_const_fn_libstd_stability.stderr
+++ b/src/test/ui/consts/min_const_fn/min_const_fn_libstd_stability.stderr
@@ -14,7 +14,7 @@ LL | const fn bar2() -> u32 { foo2() }
    |
    = help: Const-stable functions can only call other const-stable functions
 
-error: const-stable function cannot use `#[feature(const_fn)]`
+error: const-stable function cannot use `#[feature(const_fn_floating_point_arithmetic)]`
   --> $DIR/min_const_fn_libstd_stability.rs:29:26
    |
 LL | const fn bar3() -> u32 { (5f32 + 6f32) as u32 }
diff --git a/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.rs b/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.rs
index 902ed435e31..0f48341ddf3 100644
--- a/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.rs
+++ b/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.rs
@@ -3,7 +3,7 @@
             we're apparently really bad at it",
             issue = "none")]
 
-#![feature(const_fn, foo, foo2)]
+#![feature(const_fn, const_fn_floating_point_arithmetic, foo, foo2)]
 #![feature(staged_api)]
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -27,7 +27,7 @@ const unsafe fn bar2() -> u32 { unsafe { foo2() } } //~ ERROR not yet stable as
 #[rustc_const_stable(feature = "rust1", since = "1.0.0")]
 // conformity is required, even with `const_fn` feature gate
 const unsafe fn bar3() -> u32 { (5f32 + 6f32) as u32 }
-//~^ ERROR const-stable function cannot use `#[feature(const_fn)]`
+//~^ ERROR const-stable function cannot use `#[feature(const_fn_floating_point_arithmetic)]`
 
 // check whether this function cannot be called even with the feature gate active
 #[unstable(feature = "foo2", issue = "none")]
diff --git a/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.stderr b/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.stderr
index 2741a864404..1ca5964ce0f 100644
--- a/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.stderr
+++ b/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.stderr
@@ -14,7 +14,7 @@ LL | const unsafe fn bar2() -> u32 { unsafe { foo2() } }
    |
    = help: Const-stable functions can only call other const-stable functions
 
-error: const-stable function cannot use `#[feature(const_fn)]`
+error: const-stable function cannot use `#[feature(const_fn_floating_point_arithmetic)]`
   --> $DIR/min_const_unsafe_fn_libstd_stability.rs:29:33
    |
 LL | const unsafe fn bar3() -> u32 { (5f32 + 6f32) as u32 }