Inline const block is not always an expression

[DutchGhost]

The following code:

#![feature(inline_const)]

fn main() {
    dbg!(const {});
}

fails to compile, producing this error message:

error: no rules expected the token `const`
 --> src/main.rs:4:10
  |
4 |     dbg!(const {});
  |          ^^^^^ no rules expected this token in macro call

However, if the entire const {} is placed in yet another {} block, it just works:

#![feature(inline_const)]

fn main() {
  dbg!({ const {} });
}

[petrochenkov]

Closing as a duplicate of #84155 (which is newer, but has some discussion).