MS ABI: -fno-rtti-data wasn't data-free enough

While -fno-rtti-data would correctly avoid referencing the RTTI complete
object locator in the VFTable itself, it would emit them anyway.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@213841 91177308-0d34-0410-b5e6-96231b3b80d8