Strangly dyn type lifetimes in cast to `*mut dyn`

rust-analyzer version: rust-analyzer 0.4.2733-standalone

rustc version: rustc 1.94.0-nightly (4fa80a5e7 2026-01-05)

editor or extension: Vim

code snippet to reproduce:

fn foo<T: Sync>(s: *mut T) -> *mut (dyn Sync + 'static) {
    let x = s as *mut dyn Sync;
     // ^ *mut (dyn Sync + 'static)
    x // but cannot return this value
}

Did something strange happen in as?

can compile case:

fn foo<T: Sync>(s: *mut T) -> *mut (dyn Sync + 'static) {
    let x = s as *mut dyn Sync;
    todo!()
}

cannot compile case:

fn foo<T: Sync>(s: *mut T) -> *mut (dyn Sync + 'static) {
    let x = s as *mut (dyn Sync + 'static);
    todo!()
}

Start with the two Rust reproducer functions in the issue and compare rust-analyzer's inferred type for the cast with the compiler's acceptance or rejection of each return expression. The rust-analyzer and rustc versions are given in the report; done means the cast's displayed lifetime and compatibility with the declared return type are handled consistently.