[Coroutines][6/6] Clang schedules new passes

Summary:
Depends on https://reviews.llvm.org/D71902.

The last in a series of six patches that ports the LLVM coroutines
passes to the new pass manager infrastructure.

This patch has Clang schedule the new coroutines passes when the
`-fexperimental-new-pass-manager` option is used. With this and the
previous 5 patches, Clang is capable of building and successfully
running the test suite of large coroutines projects such as
https://github.com/lewissbaker/cppcoro with
`ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER=On`.

Reviewers: GorNishanov, lewissbaker, chandlerc, junparser

Subscribers: EricWF, cfe-commits, llvm-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D71903
diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 6c71cf7..b244fd4 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -49,6 +49,10 @@
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetOptions.h"
 #include "llvm/Transforms/Coroutines.h"
+#include "llvm/Transforms/Coroutines/CoroCleanup.h"
+#include "llvm/Transforms/Coroutines/CoroEarly.h"
+#include "llvm/Transforms/Coroutines/CoroElide.h"
+#include "llvm/Transforms/Coroutines/CoroSplit.h"
 #include "llvm/Transforms/IPO.h"
 #include "llvm/Transforms/IPO/AlwaysInliner.h"
 #include "llvm/Transforms/IPO/LowerTypeTests.h"
@@ -957,6 +961,22 @@
   }
 }
 
+static void addCoroutinePassesAtO0(ModulePassManager &MPM,
+                                   const LangOptions &LangOpts,
+                                   const CodeGenOptions &CodeGenOpts) {
+  if (!LangOpts.Coroutines)
+    return;
+
+  MPM.addPass(createModuleToFunctionPassAdaptor(CoroEarlyPass()));
+
+  CGSCCPassManager CGPM(CodeGenOpts.DebugPassManager);
+  CGPM.addPass(CoroSplitPass());
+  CGPM.addPass(createCGSCCToFunctionPassAdaptor(CoroElidePass()));
+  MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(std::move(CGPM)));
+
+  MPM.addPass(createModuleToFunctionPassAdaptor(CoroCleanupPass()));
+}
+
 static void addSanitizersAtO0(ModulePassManager &MPM,
                               const Triple &TargetTriple,
                               const LangOptions &LangOpts,
@@ -1076,6 +1096,7 @@
   PTO.LoopInterleaving = CodeGenOpts.UnrollLoops;
   PTO.LoopVectorization = CodeGenOpts.VectorizeLoop;
   PTO.SLPVectorization = CodeGenOpts.VectorizeSLP;
+  PTO.Coroutines = LangOpts.Coroutines;
 
   PassInstrumentationCallbacks PIC;
   StandardInstrumentations SI;
@@ -1279,6 +1300,7 @@
     }
 
     if (CodeGenOpts.OptimizationLevel == 0) {
+      addCoroutinePassesAtO0(MPM, LangOpts, CodeGenOpts);
       addSanitizersAtO0(MPM, TargetTriple, LangOpts, CodeGenOpts);
     }
   }