Rollup merge of #34495 - jseyfried:only_ident_macro_invocations, r=eddyb

Rollup merge of #34495 - jseyfried:only_ident_macro_invocations, r=eddyb

Forbid type parameters and global paths in macro invocations

Fixes #28558.
This is a [breaking-change]. For example, the following would break:
```rust
macro_rules! m { () => { () } }
fn main() {
    m::<T>!(); // Type parameters are no longer allowed in macro invocations
    ::m!(); // Global paths are no longer allowed in macro invocations
}
```
Any breakage can be fixed by removing the type parameters or the leading `::` (respectively).

r? @eddyb