Don't try to devirtualize non-virtual calls

We would end up marking the vtable of the derived class as used for no
reason. Because the call itself is qualified, it is never virtual, and
the vtable of the derived class isn't helpful. We would end up rejecting
code that MSVC accepts for no benefit.

See http://crbug.com/413478

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@217910 91177308-0d34-0410-b5e6-96231b3b80d8