ASTImporter has some bugs when it's importing types
that themselves come from an ExternalASTSource. This
is exposed particularly in the behavior when
comparing complete TagDecls with forward
declarations. This patch does several things:
- Adds a test case making sure that conflicting
forward-declarations are resolved correctly;
- Extends the clang-import-test harness to test
two-level importing, so that we make sure we
complete types when necessary; and
- Fixes a few bugs I found this way. Failure to
complete types was one; however, I also discovered
that complete RecordDecls aren't properly added to
the redecls chain for existing forward
declarations.
llvm-svn: 302975