The MicrosoftExtensions.c test file should not rely on -x objective-c++. Removed that from the RUN line, fixed obvious C++isms in the code, and moved some C++ tests into MicrosoftExtensions.cpp instead. As a drive-by, changed the line endings for MicrosoftExtensions.c to be LF instead of CRLF.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@212417 91177308-0d34-0410-b5e6-96231b3b80d8
Giving this test a triple to satisfy the build bots.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@212418 91177308-0d34-0410-b5e6-96231b3b80d8