[AMDGPU] gfx11 LDSDIR instructions MC support

Contributors:
Carl Ritson <carl.ritson@amd.com>

Patch 8/N for upstreaming of AMDGPU gfx11 architecture.

Depends on D125498

Reviewed By: critson, rampitec, #amdgpu

Differential Revision: https://reviews.llvm.org/D125820