Check the access of operator delete from the destructor context

Previously we would do the access check from the context of
MarkVTableUsed.

Also update this test to C++11, since that is typically used with the MS
C++ ABI.

Fixes PR20005.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@210850 91177308-0d34-0410-b5e6-96231b3b80d8