Serialization: Deserialize opaque type xrefs from the right extension module. #25600
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
When deserializing an opaque type xref inside an extension context, we were looking
incorrectly in the base module of the type being extended, rather than in the module
of the extension, where the opaque type would really be. Fixes rdar://problem/51775500.
This includes a small refactoring of OpaqueTypeDecl deserialization to break the inevitable
cycle between deserializing the namingDecl, and the namingDecl turning around and re-
deserializing its opaque return type. This is NFC but avoids some unnecessary work.