[llvm] [AMDGPU][NPM] Enable SIModeRegister and SIInsertHardclauses passes (PR #168831)

[Matt Arsenault via llvm-commits]

================
@@ -2365,10 +2365,10 @@ void AMDGPUCodeGenPassBuilder::addPreEmitPass(AddMachinePass &addPass) const {
   addPass(SIMemoryLegalizerPass());
   addPass(SIInsertWaitcntsPass());
 
-  // TODO: addPass(SIModeRegisterPass());
+  addPass(SIModeRegisterPass());
 
   if (TM.getOptLevel() > CodeGenOptLevel::None) {
-    // TODO: addPass(SIInsertHardClausesPass());
+    addPass(SIInsertHardClausesPass());
   }
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arsenm wrote:

```suggestion
if (TM.getOptLevel() > CodeGenOptLevel::None)
  addPass(SIInsertHardClausesPass());
```

https://github.com/llvm/llvm-project/pull/168831