[AMDGPU] gfx11 export instructions

Contributors:
Jay Foad <jay.foad@amd.com>
Dmitry Preobrazhensky <d-pre@mail.ru>

Patch 10/N for upstreaming of AMDGPU gfx11 architecture.

Depends on D125822

Reviewed By: dp

Differential Revision: https://reviews.llvm.org/D125824