`macro!();` statements sometimes don't seem to include `;` in `stmt.span` (HIR)

[jieyouxu]

cc #133833 and #133834 in suggestions such as

#![crate_type = "lib"]

fn foo() -> String {
    let mut bar = {
        unknown_macro!();
    };
    return bar;
}

Opened while looking at #133843 to not lose the FIXME.