[PowerPC] Enable machine verification for 3 passes

[ZhangKang]

Summary

For PowerPC, there are 3 passes has disabled the machine verification.

PPCTargetMachine.cpp:    addPass(&LiveVariablesID, false);
PPCTargetMachine.cpp:    addPass(createPPCEarlyReturnPass(), false);
PPCTargetMachine.cpp:  addPass(createPPCBranchSelectionPass(), false);

Three are 3 patches to fix the machine verification for PowerPC.
https://github.com/llvm/llvm-project/commit/782a4dd1a478e41857744b483b104b5e66857fbf is to fix the operand flag for ppc-early-ret pass.
https://github.com/llvm/llvm-project/commit/4bb0a1cb70732f16749df6d47fd85eb86d60f587 is to fix the liveness for ppc-expand-isel pass.
https://github.com/llvm/llvm-project/commit/302e11cd974255eafd80ee4fdf52054a00b3e4be is to fix 3 cases issues.

After upstream above 3 patches, all PowerPC pass can enable machine verification and all cases can be passes(enable EXPENSIVE_CHECKS).

This patch is to enable machine verification for above three passes.

[steven.zhang]

LGTM, thank you for enabling this.

llvm/lib/Target/PowerPC/PPCTargetMachine.cpp

void PPCPassConfig::addPreRegAlloc() {
   }
 
   // FIXME: We probably don't need to run these for -fPIE.
   if (getPPCTargetMachine().isPositionIndependent()) {
     // FIXME: LiveVariables should not be necessary here!
     // PPCTLSDynamicCallPass uses LiveIntervals which previously dependent on
     // LiveVariables. This (unnecessary) dependency has been removed now,
     // however a stage-2 clang build fails without LiveVariables computed here.
-    addPass(&LiveVariablesID, false);
+    addPass(&LiveVariablesID);
     addPass(createPPCTLSDynamicCallPass());
   }
   if (EnableExtraTOCRegDeps)
     addPass(createPPCTOCRegDepsPass());
 
   if (getOptLevel() != CodeGenOpt::None)
     addPass(&MachinePipelinerID);
 }
void PPCPassConfig::addPreSched2() {
   }
 }
 
 void PPCPassConfig::addPreEmitPass() {
   addPass(createPPCPreEmitPeepholePass());
   addPass(createPPCExpandISELPass());
 
   if (getOptLevel() != CodeGenOpt::None)
-    addPass(createPPCEarlyReturnPass(), false);
+    addPass(createPPCEarlyReturnPass());
   // Must run branch selection immediately preceding the asm printer.
-  addPass(createPPCBranchSelectionPass(), false);
+  addPass(createPPCBranchSelectionPass());
 }
 
 TargetTransformInfo
 PPCTargetMachine::getTargetTransformInfo(const Function &F) {
   return TargetTransformInfo(PPCTTIImpl(this, F));
 }
 
 static MachineSchedRegistry
 PPCPreRASchedRegistry("ppc-prera",
                       "Run PowerPC PreRA specific scheduler",
                       createPPCMachineScheduler);
 
 static MachineSchedRegistry
 PPCPostRASchedRegistry("ppc-postra",
                        "Run PowerPC PostRA specific scheduler",
                        createPPCPostMachineScheduler);