Revert "Populate effective visibilities in `rustc_privacy`"
This reverts commit cff85f22f5, cc #110907. It needs to be fixed, but there are too many issues being reported that I wanted to put up a revert until a proper fix can be committed.
Fixes a ton of issues where private but still reachable impls were missing during codegen:
Fixes #111320
Fixes #111321
Fixes #111334
Fixes #111357
Fixes #111368
Fixes #111373
Fixes #111377
Fixes #111386
Fixes #111387
`@bors` p=1
r? `@petrochenkov`