In Microsoft mode, make "Unqualified lookup into dependent bases of class templates" works  inside default argument instantiation.

This is a little bit tricky because during default argument instantiation the CurContext points to a CXXMethodDecl but we can't use the keyword this or have an implicit member call generated.

This fixes 2 errors when parsing MFC code with clang.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@144881 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed