RTTI Uniqueness: remove __name_for_load function.

It's identical to name() these days. (At one point it avoided masking
of the RTTI uniqueness bit because ARM64 ignored it architecturally,
but no longer).

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@205518 91177308-0d34-0410-b5e6-96231b3b80d8