Auto merge of #63870 - estebank:async-fn-call, r=oli-obk

Suggest call fn ctor passed as arg to fn with type param bounds

_Reviewer note: the relevant changes are in the second commit, the first is simple and mechanical, but verbose._

When forgetting to call a fn in an argument position to an fn that has a generic bound:

```rust
async fn foo() {}

fn bar(f: impl Future<Output=()>) {}

fn main() {
    bar(foo); // <- should be `bar(foo());`
}
```

suggest calling it:

```
error[E0277]: the trait bound `fn() -> impl std::future::Future {foo}: std::future::Future` is not satisfied
  --> $DIR/async-fn-ctor-passed-as-arg-where-it-should-have-been-called.rs:9:5
   |
LL | fn bar(f: impl Future<Output=()>) {}
   | --------------------------------- required by `bar`
...
LL |     bar(foo);
   |     ^^^ the trait `std::future::Future` is not implemented for `fn() -> impl std::future::Future {foo}`
   |
   = help: it looks like you forgot to use parentheses to call the function: `foo()`
```

Fix #63100. Follow up to #63833 and #63337.

1 files changed, 3 insertions, 6 deletions

diff --git a/src/test/ui/traits/trait-static-method-generic-inference.stderr b/src/test/ui/traits/trait-static-method-generic-inference.stderr
index 390d21c4a69..a99536d31ef 100644
--- a/src/test/ui/traits/trait-static-method-generic-inference.stderr
+++ b/src/test/ui/traits/trait-static-method-generic-inference.stderr
@@ -1,14 +1,11 @@
 error[E0283]: type annotations required: cannot resolve `_: base::HasNew<base::Foo>`
   --> $DIR/trait-static-method-generic-inference.rs:24:25
    |
+LL |         fn new() -> T;
+   |         -------------- required by `base::HasNew::new`
+...
 LL |     let _f: base::Foo = base::HasNew::new();
    |                         ^^^^^^^^^^^^^^^^^
-   |
-note: required by `base::HasNew::new`
-  --> $DIR/trait-static-method-generic-inference.rs:8:9
-   |
-LL |         fn new() -> T;
-   |         ^^^^^^^^^^^^^^
 
 error: aborting due to previous error