Rollup merge of #134661 - dtolnay:prefixattr, r=fmease

Reduce precedence of expressions that have an outer attr

Previously, `-Zunpretty=expanded` would expand this program as follows:

```rust
#![feature(stmt_expr_attributes)]

macro_rules! repro {
    ($e:expr) => {
        #[allow(deprecated)] $e
    };
}

#[derive(Default)]
struct Thing {
    #[deprecated]
    field: i32,
}

fn main() {
    let thing = Thing::default();
    let _ = repro!(thing).field;
}
```

```rs
#![feature(prelude_import)]
#![feature(stmt_expr_attributes)]
#[prelude_import]
use std::prelude::rust_2021::*;
#[macro_use]
extern crate std;

struct Thing {
    #[deprecated]
    field: i32,
}

#[automatically_derived]
impl ::core::default::Default for Thing {
    #[inline]
    fn default() -> Thing {
        Thing { field: ::core::default::Default::default() }
    }
}

fn main() {
    let thing = Thing::default();
    let _ = #[allow(deprecated)] thing.field;
}
```

This is not the correct expansion. The correct output would have `(#[allow(deprecated)] thing).field` with the attribute applying only to `thing`, not to `thing.field`.

0 files changed, 0 insertions, 0 deletions