Allow target to specify early module passes

[rampitec]

Summary

Call addEarlyAsPossiblePasses to populate module passes from BackendUtil.

This patch depends on the llvm's counterpart D28031.

lib/CodeGen/BackendUtil.cpp

void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
   PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
   PMBuilder.PrepareForThinLTO = CodeGenOpts.EmitSummaryIndex;
   PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
   PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
 
   MPM.add(new TargetLibraryInfoWrapperPass(*TLII));
 
   // Add target-specific passes that need to run as early as possible.
-  if (TM)
+  if (TM) {
     PMBuilder.addExtension(
         PassManagerBuilder::EP_EarlyAsPossible,
         [&](const PassManagerBuilder &, legacy::PassManagerBase &PM) {
-          TM->addEarlyAsPossiblePasses(PM);
+          TM->addEarlyAsPossiblePasses(PM, PMT_FunctionPassManager);
+        });
+
+    PMBuilder.addExtension(
+        PassManagerBuilder::EP_ModuleOptimizerEarly,
+        [&](const PassManagerBuilder &, legacy::PassManagerBase &PM) {
+          TM->addEarlyAsPossiblePasses(PM, PMT_ModulePassManager);
         });
+  }
 
   PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
                          addAddDiscriminatorsPass);
 
   // In ObjC ARC mode, add the main ARC optimization passes.
   if (LangOpts.ObjCAutoRefCount) {
     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
                            addObjCARCExpandPass);