type_info objects are not unnamed_addr: the ABI requires us to
unique them and permits the implementation of dynamic_cast (and
anything else which knows it's working with a complete class
type) to compare their addresses directly.

rdar://16005328

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@201020 91177308-0d34-0410-b5e6-96231b3b80d8