Fix regression from r185450.

As it turns out, the NoFunction bit for local class mangling needed to be
propagated into more places. r185450 turned what used to be an incorrect
mangling into an assertion.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185713 91177308-0d34-0410-b5e6-96231b3b80d8