[llvm] [AMDGPU] Support v_lshl_add_u64 in gfx1250 (PR #145591)

[Changpeng Fang via llvm-commits]

https://github.com/changpeng approved this pull request.

LGTM with concern for the future with both SubtargetPredicate and OtherPredicates used in VOP3Inst.

https://github.com/llvm/llvm-project/pull/145591