[AMDGPU][MC][GFX9] Added 16-bit renamed and "_legacy" VALU opcodes

See Bug 33629: https://bugs.llvm.org//show_bug.cgi?id=33629

Reviewers: vpykhtin, SamWot, arsenm

Differential Revision: https://reviews.llvm.org/D36322

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310497 91177308-0d34-0410-b5e6-96231b3b80d8
10 files changed