[AMDGPU] Disassembler: fix for disaasembling v_mac_f32/16_dpp/sdwa

Summary: Real instruction should copy constraints from real instruction. This allows auto-generated disassembler to correctly process tied operands.

Reviewers: nhaustov, vpykhtin, tstellarAMD

Subscribers: arsenm, kzhuravl, wdng, nhaehnle, yaxunl, tony-tye

Differential Revision: https://reviews.llvm.org/D27847

llvm-svn: 290336