[LegacyPM] remove unset variables in PassManagerBuilder

[goncharov]

Summary

D137915 stopped setting this variables but NewGVN was still used and caused asan failure

[mehdi_amini]

llvm/lib/Transforms/IPO/PassManagerBuilder.cpp

237

There is no way to enable NewGVNPass anymore? Is this intended?

[aeubanks]

llvm/lib/Transforms/IPO/PassManagerBuilder.cpp

237

PassManagerBuilder is deprecated (legacy PM for optimization pipeline is deprecated) and I'm in the process of removing it

llvm/include/llvm/Transforms/IPO/PassManagerBuilder.h

public:
   /// tests.
   const ModuleSummaryIndex *ImportSummary = nullptr;
 
   bool DisableUnrollLoops;
   bool CallGraphProfile;
   bool SLPVectorize;
   bool LoopVectorize;
   bool LoopsInterleaved;
-  bool RerollLoops;
-  bool NewGVN;
   bool DisableGVNLoadPRE;
   bool ForgetAllSCEVInLoopUnroll;
   bool VerifyInput;
   bool VerifyOutput;
   bool MergeFunctions;
   bool DivergentTarget;
   unsigned LicmMssaOptCap;
   unsigned LicmMssaNoAccForPromotionCap;

llvm/lib/Transforms/IPO/PassManagerBuilder.cpp

void PassManagerBuilder::addFunctionSimplificationPasses(
   addExtensionsToPM(EP_LoopOptimizerEnd, MPM);
   // This ends the loop pass pipelines.
 
   // Break up allocas that may now be splittable after loop unrolling.
   MPM.add(createSROAPass());
 
   if (OptLevel > 1) {
     MPM.add(createMergedLoadStoreMotionPass()); // Merge ld/st in diamonds
-    MPM.add(NewGVN ? createNewGVNPass()
-                   : createGVNPass(DisableGVNLoadPRE)); // Remove redundancies
+    MPM.add(createGVNPass(DisableGVNLoadPRE));  // Remove redundancies
   }
   MPM.add(createSCCPPass());                  // Constant prop with SCCP
 
   // Delete dead bit computations (instcombine runs after to fold away the dead
   // computations, and then ADCE will run later to exploit any new DCE
   // opportunities that creates).
   MPM.add(createBitTrackingDCEPass());        // Delete dead bit computations