The previous implementation did not work when called on an opening
delimiter, or when called re-entrantly from the same `TokenCursor` stack
depth.

We store store the `DefId` directly in `ExpnData`. This will allow us to
serialize `ExpnData` in PR rust-lang#72121 without needing to manage a side
table.

call_one_force -> call_once_force

… r=petrochenkov

Remove `macro_defs` map

We now store the `DefId` directly in `ExpnKind::Macro`. This will allow
us to serialize `ExpnData` in PR rust-lang#72121 without needing to manage a side
table.

…okens, r=petrochenkov

Rewrite `Parser::collect_tokens`

The previous implementation did not work when called on an opening
delimiter, or when called re-entrantly from the same `TokenCursor` stack
depth.

I'm not sure how to test this apart from rust-lang#72287

Fix typo in doc comment.

call_one_force -> call_on**c**e_force