[EH] Improve catch validation (#4315)

This improves validation of `catch` bodies mostly by checking the
validity of `pop`s.

For every `catch` body:
- Checks if its tag exists
- If the tag's type is none:
  - Ensures there shouldn't be any `pop`s
- If the tag's type is not none:
  - Checks if there's a single `pop` within the catch body
  - Checks if the tag type matches the `pop`'s type
  - Checks if the `pop`'s location is valid

For every `catch_all` body:
- Ensures there shuldn't be any `pop`s

This uncovers several bugs related to `pop`s in existing tests, which
this PR also fixes.

0 files changed, 0 insertions, 0 deletions