[llvm] [AMDGPU] New GFX11+ aliases v_dot4_i32_i8 and v_dot8_i32_i4 (PR #118997)

[Georg Lehmann via llvm-commits]

DadSchoorse wrote:

wouldn't it make sense to set `neg_lo:[1,1,0]` by default for these opcodes? Then they would behave like gfx9/10 opcodes with the same names. 

https://github.com/llvm/llvm-project/pull/118997