[SPARC][IAS] Add support for %uhi and %ulo extensions

This adds support for GNU %uhi and %ulo extensions.
Those resolve to the same relocations as %hh and %hm.

Reviewers:
cyndyishida, dcci, brad0, jrtc27, aaupov, Endilll, rorth, maksfb, #reviewers-libcxxabi, s-barannikov, rafaelauler, ayermolo, #reviewers-libunwind, #reviewers-libcxx, daniel-grumberg, tbaederr

Reviewed By: s-barannikov

Pull Request: https://github.com/llvm/llvm-project/pull/94246