[MS-ABI] Implement typeid
This patch enables clang to generate calls to __RTtypeid when lowering 
typeid on win32 targets.  Test cases are included.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211223 91177308-0d34-0410-b5e6-96231b3b80d8