clang-cl: Disable TBAA by default for MSVC compatibility

MSVC doesn't have an option to enable TBAA, so make -fstrict-aliasing
and -fno-strict-aliasing available in clang-cl.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@205924 91177308-0d34-0410-b5e6-96231b3b80d8