swift

07319d0f - [ASTScope] Teach ASTScope lookup to find source locations inside macro-expanded

[ASTScope] Teach ASTScope lookup to find source locations inside macro-expanded scopes. ASTScope lookup can no longer assume that all scopes are within the same source file. Scope trees can now contain scopes that are in macro expansion buffers, which live in different source files with independent source ranges from the root of a given scope tree. To handle this when searching for a scope containing a given source location, ASTScope lookup needs to walk up the chain of macro expansion buffers to find the lowest common buffer in which to compare source locations. This fixes a number of issues with unqualified lookup into and from within macro-expanded code.