[-cxx-abi microsoft] Mangle UUIDs correctly, stick them in the proper section

Revert r188055 which reverted r188053. An unrelated change previously snuck in.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188060 91177308-0d34-0410-b5e6-96231b3b80d8