Add support to fallback on operator new when a placement operator new[] is called for which there is no valid declaration.  This fallback only happens in Microsoft compatibility mode.  This patch addresses PR13164, and improves support for the WDK.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@182905 91177308-0d34-0410-b5e6-96231b3b80d8