In #99726, `-fptrauth-type-info-vtable-pointer-discrimination` was
introduced, which is intended to enable type and address discrimination
for type_info vtable pointers. However, some codegen logic for actually
enabling address discrimination was missing. This patch addresses the
issue.
Fixes#101716
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
llvm-svn: 201020
