tsan: remove dependencies on HAS_48_BIT_ADDRESS_SPACE and Mapping

Remove direct uses of Mapping in preperation for removing Mapping type
(which we already don't have for all platforms).
Remove dependence on HAS_48_BIT_ADDRESS_SPACE in preparation for removing it.
As far as I see for Apple/Mac platforms !HAS_48_BIT_ADDRESS_SPACE
simply means SANITIZER_IOS.

Depends on D107741.

Reviewed By: melver

Differential Revision: https://reviews.llvm.org/D107742