swift

3dfd988c - [Serialization] Mark decls that can never be cross-referenced (#17301)

[Serialization] Mark decls that can never be cross-referenced (#17301) This allows us to filter them out in cases that would otherwise be ambiguous. The particular prompting situation looks a lot like the test case: a protocol, plus a forward-declared class with the same name. (Normally we ignore forward-declared classes, but SourceKit's module interface generation feature makes dummy ClassDecls for them instead.) https://bugs.swift.org/browse/SR-4851 (cherry picked from commit 05d0a2dfefcdfd0c6feeef1840337885e4bfce87)