[llvm] AMDGPU/UniformityAnalysis: For G_AMDGPU_WHOLE_WAVE_FUNC_SETUP, always divergent (PR #203000)

[Matt Arsenault via llvm-commits]

================
@@ -10992,6 +10992,10 @@ SIInstrInfo::getGenericValueUniformity(const MachineInstr &MI) const {
   if (Opcode == TargetOpcode::G_DYN_STACKALLOC)
     return ValueUniformity::AlwaysUniform;
 
+  if (Opcode == AMDGPU::G_AMDGPU_WHOLE_WAVE_FUNC_SETUP) {
+    return ValueUniformity::NeverUniform;
+  }
----------------
arsenm wrote:

```suggestion
  if (Opcode == AMDGPU::G_AMDGPU_WHOLE_WAVE_FUNC_SETUP)
    return ValueUniformity::NeverUniform;
```

https://github.com/llvm/llvm-project/pull/203000