[NFC] Rename EmitAssemblyHelper new/legacy PM methods

[aeubanks]

Summary

To reflect the fact that the new PM is the default now.

[MaskRay]

Consider switching to functionName while updating the function names.

[MaskRay]

clang/lib/CodeGen/BackendUtil.cpp

175

Perhaps add a comment to bring awareness to possible downstream users

[aeubanks]

add comment
I'd rather switch everything to lowerCamel at once rather than just a few methods

clang/lib/CodeGen/BackendUtil.cpp

public:
 
   ~EmitAssemblyHelper() {
     if (CodeGenOpts.DisableFree)
       BuryPointer(std::move(TM));
   }
 
   std::unique_ptr<TargetMachine> TM;
 
-  void EmitAssembly(BackendAction Action,
+  // Emit output using the legacy pass manager for the optimization pipeline.
+  // This will be removed soon when using the legacy pass manager for the
+  // optimization pipeline is no longer supported.
+  void EmitAssemblyWithLegacyPassManager(BackendAction Action,
                                          std::unique_ptr<raw_pwrite_stream> OS);
 
-  void EmitAssemblyWithNewPassManager(BackendAction Action,
-                                      std::unique_ptr<raw_pwrite_stream> OS);
+  // Emit output using the new pass manager for the optimization pipeline. This
+  // is the default.
+  void EmitAssembly(BackendAction Action,
 };
 
 // We need this wrapper to access LangOpts and CGOpts from extension functions
 // that we add to the PassManagerBuilder.
 class PassManagerBuilderWrapper : public PassManagerBuilder {
 public:
   PassManagerBuilderWrapper(const Triple &TargetTriple,
                             const CodeGenOptions &CGOpts,
if (TM->addPassesToEmitFile(CodeGenPasses, OS, DwoOS, CGFT,
                               /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
     Diags.Report(diag::err_fe_unable_to_interface_with_target);
     return false;
   }
 
   return true;
 }
 
-void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
-                                      std::unique_ptr<raw_pwrite_stream> OS) {
+void EmitAssemblyHelper::EmitAssemblyWithLegacyPassManager(
+    BackendAction Action, std::unique_ptr<raw_pwrite_stream> OS) {
   TimeRegion Region(CodeGenOpts.TimePasses ? &CodeGenerationTime : nullptr);
 
   setCommandLineOpts(CodeGenOpts);
 
   bool UsesCodeGen = (Action != Backend_EmitNothing &&
                       Action != Backend_EmitBC &&
                       Action != Backend_EmitLL);
   CreateTargetMachine(UsesCodeGen);

 /// A clean version of `EmitAssembly` that uses the new pass manager.
 ///
 /// Not all features are currently supported in this system, but where
 /// necessary it falls back to the legacy pass manager to at least provide
 /// basic functionality.
 ///
 /// This API is planned to have its functionality finished and then to replace
 /// `EmitAssembly` at some point in the future when the default switches.
-void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
-    BackendAction Action, std::unique_ptr<raw_pwrite_stream> OS) {
+void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
+                                      std::unique_ptr<raw_pwrite_stream> OS) {
   TimeRegion Region(CodeGenOpts.TimePasses ? &CodeGenerationTime : nullptr);
   setCommandLineOpts(CodeGenOpts);
 
   bool RequiresCodeGen = (Action != Backend_EmitNothing &&
                           Action != Backend_EmitBC && Action != Backend_EmitLL);
   CreateTargetMachine(RequiresCodeGen);
 
   if (RequiresCodeGen && !TM)
if (CombinedIndex) {
       EmptyModule = std::make_unique<llvm::Module>("empty", M->getContext());
       EmptyModule->setTargetTriple(M->getTargetTriple());
       M = EmptyModule.get();
     }
   }
 
   EmitAssemblyHelper AsmHelper(Diags, HeaderOpts, CGOpts, TOpts, LOpts, M);
 
-  if (!CGOpts.LegacyPassManager)
-    AsmHelper.EmitAssemblyWithNewPassManager(Action, std::move(OS));
+  if (CGOpts.LegacyPassManager)
+    AsmHelper.EmitAssemblyWithLegacyPassManager(Action, std::move(OS));
   else
     AsmHelper.EmitAssembly(Action, std::move(OS));
 
   // Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
   // DataLayout.
   if (AsmHelper.TM) {
     std::string DLDesc = M->getDataLayout().getStringRepresentation();
     if (DLDesc != TDesc) {