Auto merge of #27297 - mitaa:cleanup_E0005, r=alexcrichton

This does two things:
* removes ast::LocalSource, where only one variant was used because for-loop expansion has changed. One reason that this slipped into here is because the code in `check_local` which checks for `LocalSource::LocalFor` would report the same error as in `check_exhaustive` while using the wrong error code (E0005 instead of E0297).
* silences the warning about already used diagnostic code E0005 (fixes #27279)

passes `make check` locally.

0 files changed, 0 insertions, 0 deletions