It never makes sense to do a lookup into a LinkageSpecDecl, so assert that we
don't, and clean up the places that do it.

The change to ASTWriter is surprising, but the deleted code is a no-op as of
r152608.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@152609 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed