[clang] [llvm] [AMDGPU] Add dot product patterns with saturating add (clamp) (PR #187945)

[via cfe-commits]

addmisol wrote:

till now with this pr's changes, these dot patterns with are recognized for these compared to the main branch:

for dot2
  - udot2_sat
  - sdot2_sat 

for dot4
  - test_udot4_sat 
  - test_sdot4_sat 
  - test_udot4_unsat 
  - test_sdot4_unsat 

https://github.com/llvm/llvm-project/pull/187945