[llvm] [AMDGPU][TTI] Add target hook for the custom instruction uniformity (PR #137639)

[Pankaj Dwivedi via llvm-commits]

================
@@ -23,7 +23,10 @@ enum class InstructionUniformity {
   AlwaysUniform,
 
   /// The result values can never be assumed to be uniform.
-  NeverUniform
+  NeverUniform,
+
+  /// Result value can be uniform if either of first two operand are uniform.
+  EitherOfFirstTwoOp
----------------
PankajDwivedi-25 wrote:

sounds good, will `anyOfFirstTwoUseOp` be ok?

https://github.com/llvm/llvm-project/pull/137639