[nfc] simplify promoteIndirectCalls

[mtrofin]

Summary

There's no caller to promoteIndirectCalls that would pass a nullptr
ModuleAnalysisManager, so passing it by reference does away with a
bunch of nullptr tests, and also removes the need for a "OwnedORE".

[xur]

LGTM. Thanks for the cleanup!

llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp

for (auto *CB : findIndirectCalls(F)) {
     // Otherwise we need update with the un-promoted records back.
     annotateValueSite(*M, *CB, ICallProfDataRef.slice(NumPromoted), TotalCount,
                       IPVK_IndirectCallTarget, NumCandidates);
   }
   return Changed;
 }
 
 // A wrapper function that does the actual work.
-static bool promoteIndirectCalls(Module &M, ProfileSummaryInfo *PSI,
-                                 bool InLTO, bool SamplePGO,
-                                 ModuleAnalysisManager *AM = nullptr) {
+static bool promoteIndirectCalls(Module &M, ProfileSummaryInfo *PSI, bool InLTO,
+                                 bool SamplePGO, ModuleAnalysisManager &AM) {
   if (DisableICP)
     return false;
   InstrProfSymtab Symtab;
   if (Error E = Symtab.create(M, InLTO)) {
     std::string SymtabFailure = toString(std::move(E));
     M.getContext().emitError("Failed to create symtab: " + SymtabFailure);
     return false;
   }
   bool Changed = false;
   for (auto &F : M) {
     if (F.isDeclaration() || F.hasOptNone())
       continue;
 
-    std::unique_ptr<OptimizationRemarkEmitter> OwnedORE;
-    OptimizationRemarkEmitter *ORE;
-    if (AM) {
-      auto &FAM =
-          AM->getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
-      ORE = &FAM.getResult<OptimizationRemarkEmitterAnalysis>(F);
-    } else {
-      OwnedORE = std::make_unique<OptimizationRemarkEmitter>(&F);
-      ORE = OwnedORE.get();
-    }
+        AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
+    auto &ORE = FAM.getResult<OptimizationRemarkEmitterAnalysis>(F);
 
-    ICallPromotionFunc ICallPromotion(F, &M, &Symtab, SamplePGO, *ORE);
+    ICallPromotionFunc ICallPromotion(F, &M, &Symtab, SamplePGO, ORE);
     bool FuncChanged = ICallPromotion.processFunction(PSI);
     if (ICPDUMPAFTER && FuncChanged) {
       LLVM_DEBUG(dbgs() << "\n== IR Dump After =="; F.print(dbgs()));
       LLVM_DEBUG(dbgs() << "\n");
     }
     Changed |= FuncChanged;
     if (ICPCutOff != 0 && NumOfPGOICallPromotion >= ICPCutOff) {
       LLVM_DEBUG(dbgs() << " Stop: Cutoff reached.\n");
       break;
     }
   }
   return Changed;
 }
 
 PreservedAnalyses PGOIndirectCallPromotion::run(Module &M,
                                                 ModuleAnalysisManager &AM) {
   ProfileSummaryInfo *PSI = &AM.getResult<ProfileSummaryAnalysis>(M);
 
   if (!promoteIndirectCalls(M, PSI, InLTO | ICPLTOMode,
-                            SamplePGO | ICPSamplePGOMode, &AM))
+                            SamplePGO | ICPSamplePGOMode, AM))
     return PreservedAnalyses::all();
 
   return PreservedAnalyses::none();
 }