Rollup merge of #94868 - dtolnay:noblock, r=Dylan-DPC

Format core and std macro rules, removing needless surrounding blocks

Many of the asserting and printing macros in `core` and `std` are written with prehistoric-looking formatting, like this:

https://github.com/rust-lang/rust/blob/335ffbfa547df94ac236f5c56130cecf99c8d82b/library/std/src/macros.rs#L96-L101

In modern Rust style this would conventionally be written as follows instead, always using braces and a trailing semicolon on the macro arms:

https://github.com/rust-lang/rust/blob/af53809c874e0afb7be966df4d3cfcaa05277c53/library/std/src/macros.rs#L98-L105

Getting rid of the unneeded braces inside the expansion reduces extraneous indentation in macro-expanded code. For example:

```rust
println!("repro {}", true);
```

```rust
// before:

{
    ::std::io::_print(
        ::core::fmt::Arguments::new_v1(
            &["repro ", "\n"],
            &[::core::fmt::ArgumentV1::new_display(&true)],
        ),
    );
};
```

```rust
// after:

::std::io::_print(
    ::core::fmt::Arguments::new_v1(
        &["repro ", "\n"],
        &[::core::fmt::ArgumentV1::new_display(&true)],
    ),
);
```

1 files changed, 1 insertions, 1 deletions

diff --git a/src/test/ui/pattern/usefulness/tuple-struct-nonexhaustive.stderr b/src/test/ui/pattern/usefulness/tuple-struct-nonexhaustive.stderr
index fc0430d06fa..e2a65ff8524 100644
--- a/src/test/ui/pattern/usefulness/tuple-struct-nonexhaustive.stderr
+++ b/src/test/ui/pattern/usefulness/tuple-struct-nonexhaustive.stderr
@@ -12,7 +12,7 @@ LL | struct Foo(isize, isize);
    = note: the matched value is of type `Foo`
 help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown
    |
-LL ~         Foo(2, b) => println!("{}", b)
+LL ~         Foo(2, b) => println!("{}", b),
 LL +         Foo(_, _) => todo!()
    |