Unrolled build for #158518

Rollup merge of #158518 - ElectrifyPro:20777-thing, r=JonathanBrouwer

Fix mixed use of "a" / "an" article in E0277

This PR fixes a tiny little annoyance typo in error E0277. Currently, this code fails to compile (correctly) with the following error:

```rs
struct A<F: Fn()>(F);

impl<F> A<F> {}

fn main() {}
```

```rs
error[E0277]: expected a `Fn()` closure, found `F`
 --> src/main.rs:3:9
  |
3 | impl<F> A<F> {}
  |         ^^^^ expected an `Fn()` closure, found `F`
  |
  = note: wrap the `F` in a closure with no arguments: `|| { /* code */ }`
... truncated
```

Unfortunately, the first line of the error message uses the article "a", when it should be "an" for the `Fn` trait and friends. The help label does use the correct article, "an".

Unless if I have been pronouncing `Fn` incorrectly...

Author: rust-timer

library/core/src/ops/function.rs

@@ -67,7 +67,7 @@ use crate::marker::Tuple;
         // SAFETY: tidy is not smart enough to tell that the below unsafe block is a string
         label = "call the function in a closure: `|| unsafe {{ /* code */ }}`"
     ),
-    message = "expected a `{This:resolved}` closure, found `{Self}`",
+    message = "expected an `{This:resolved}` closure, found `{Self}`",
     label = "expected an `{This:resolved}` closure, found `{Self}`"
 )]
 #[fundamental] // so that regex can rely that `&str: !FnMut`
@@ -154,7 +154,7 @@ pub const trait Fn<Args: Tuple>: [const] FnMut<Args> {
         // SAFETY: tidy is not smart enough to tell that the below unsafe block is a string
         label = "call the function in a closure: `|| unsafe {{ /* code */ }}`"
     ),
-    message = "expected a `{This:resolved}` closure, found `{Self}`",
+    message = "expected an `{This:resolved}` closure, found `{Self}`",
     label = "expected an `{This:resolved}` closure, found `{Self}`"
 )]
 #[fundamental] // so that regex can rely that `&str: !FnMut`
@@ -233,7 +233,7 @@ pub const trait FnMut<Args: Tuple>: FnOnce<Args> {
         // SAFETY: tidy is not smart enough to tell that the below unsafe block is a string
         label = "call the function in a closure: `|| unsafe {{ /* code */ }}`"
     ),
-    message = "expected a `{This:resolved}` closure, found `{Self}`",
+    message = "expected an `{This:resolved}` closure, found `{Self}`",
     label = "expected an `{This:resolved}` closure, found `{Self}`"
 )]
 #[fundamental] // so that regex can rely that `&str: !FnMut`

tests/ui/abi/bad-custom.rs

@@ -100,7 +100,7 @@ async unsafe extern "custom" fn no_async_fn() {
 }
 
 fn no_promotion_to_fn_trait(f: unsafe extern "custom" fn()) -> impl Fn()  {
-    //~^ ERROR expected a `Fn()` closure, found `unsafe extern "custom" fn()`
+    //~^ ERROR expected an `Fn()` closure, found `unsafe extern "custom" fn()`
     f
 }
 

tests/ui/abi/bad-custom.stderr

@@ -184,7 +184,7 @@ LL + #[unsafe(naked)]
 LL | async unsafe extern "custom" fn no_async_fn() {
    |
 
-error[E0277]: expected a `Fn()` closure, found `unsafe extern "custom" fn()`
+error[E0277]: expected an `Fn()` closure, found `unsafe extern "custom" fn()`
   --> $DIR/bad-custom.rs:102:64
    |
 LL | fn no_promotion_to_fn_trait(f: unsafe extern "custom" fn()) -> impl Fn()  {

tests/ui/associated-types/normalization-ice-issue-149746.rs

@@ -4,14 +4,14 @@ trait Owner { type Ty<T: FnMut()>; }
 impl Owner for () { type Ty<T: FnMut()> = T; }
 pub struct Warns<T> {
     _significant_drop: <() as Owner>::Ty<T>,
-    //~^ ERROR expected a `FnMut()` closure, found `T`
+    //~^ ERROR expected an `FnMut()` closure, found `T`
     field: String,
 }
 pub fn test<T>(w: Warns<T>) {
-    //~^ ERROR expected a `FnMut()` closure, found `T`
+    //~^ ERROR expected an `FnMut()` closure, found `T`
     _ = || w.field
-    //~^ ERROR expected a `FnMut()` closure, found `T`
-    //~| ERROR expected a `FnMut()` closure, found `T`
+    //~^ ERROR expected an `FnMut()` closure, found `T`
+    //~| ERROR expected an `FnMut()` closure, found `T`
     //~| WARN: changes to closure capture in Rust 2021 will affect drop order
 }
 fn main() {}

tests/ui/associated-types/normalization-ice-issue-149746.stderr

@@ -1,4 +1,4 @@
-error[E0277]: expected a `FnMut()` closure, found `T`
+error[E0277]: expected an `FnMut()` closure, found `T`
   --> $DIR/normalization-ice-issue-149746.rs:6:24
    |
 LL |     _significant_drop: <() as Owner>::Ty<T>,
@@ -35,7 +35,7 @@ help: add a dummy let to cause `w` to be fully captured
 LL |     _ = || { let _ = &w; w.field }
    |            +++++++++++++         +
 
-error[E0277]: expected a `FnMut()` closure, found `T`
+error[E0277]: expected an `FnMut()` closure, found `T`
   --> $DIR/normalization-ice-issue-149746.rs:12:9
    |
 LL |     _ = || w.field
@@ -48,7 +48,7 @@ note: required by a bound in `Owner::Ty`
 LL | trait Owner { type Ty<T: FnMut()>; }
    |                          ^^^^^^^ required by this bound in `Owner::Ty`
 
-error[E0277]: expected a `FnMut()` closure, found `T`
+error[E0277]: expected an `FnMut()` closure, found `T`
   --> $DIR/normalization-ice-issue-149746.rs:10:16
    |
 LL | pub fn test<T>(w: Warns<T>) {
@@ -61,7 +61,7 @@ note: required by a bound in `Owner::Ty`
 LL | trait Owner { type Ty<T: FnMut()>; }
    |                          ^^^^^^^ required by this bound in `Owner::Ty`
 
-error[E0277]: expected a `FnMut()` closure, found `T`
+error[E0277]: expected an `FnMut()` closure, found `T`
   --> $DIR/normalization-ice-issue-149746.rs:12:9
    |
 LL |     _ = || w.field

tests/ui/async-await/async-fn/impl-header.rs

@@ -6,7 +6,7 @@ impl async Fn<()> for F {}
 //~^ ERROR `async` trait implementations are unsupported
 //~| ERROR the precise format of `Fn`-family traits' type parameters is subject to change
 //~| ERROR manual implementations of `Fn` are experimental
-//~| ERROR expected a `FnMut()` closure, found `F`
+//~| ERROR expected an `FnMut()` closure, found `F`
 //~| ERROR not all trait items implemented, missing: `call`
 
 fn main() {}

tests/ui/async-await/async-fn/impl-header.stderr

@@ -30,7 +30,7 @@ LL | impl async Fn<()> for F {}
    |
    = help: implement the missing item: `fn call(&self, _: ()) -> <Self as FnOnce<()>>::Output { todo!() }`
 
-error[E0277]: expected a `FnMut()` closure, found `F`
+error[E0277]: expected an `FnMut()` closure, found `F`
   --> $DIR/impl-header.rs:5:23
    |
 LL | impl async Fn<()> for F {}

tests/ui/cast/raw-ptr-to-dyn-fn-raw-ptr.rs

@@ -4,6 +4,6 @@ fn main() {
     let ptr: *mut () = core::ptr::null_mut();
     let _: &mut dyn Fn() = unsafe {
         &mut *(ptr as *mut dyn Fn())
-        //~^ ERROR expected a `Fn()` closure, found `()`
+        //~^ ERROR expected an `Fn()` closure, found `()`
     };
 }

tests/ui/cast/raw-ptr-to-dyn-fn-raw-ptr.stderr

@@ -1,4 +1,4 @@
-error[E0277]: expected a `Fn()` closure, found `()`
+error[E0277]: expected an `Fn()` closure, found `()`
   --> $DIR/raw-ptr-to-dyn-fn-raw-ptr.rs:6:16
    |
 LL |         &mut *(ptr as *mut dyn Fn())

tests/ui/closures/closure-expected.rs

@@ -1,5 +1,5 @@
 fn main() {
     let x = Some(1);
     let y = x.or_else(4);
-    //~^ ERROR expected a `FnOnce()` closure, found `{integer}`
+    //~^ ERROR expected an `FnOnce()` closure, found `{integer}`
 }