[clang][NewPM] Move EntryExitInstrumenterPass to the start of the pipeline

[leonardchan]

Summary

This fixes CodeGen/x86_64-instrument-functions.c when running under the new pass manager. The pass should go before any other pass to prevent __cyg_profile_func_enter/exit() from not being emitted by inlined functions.

[chandlerc]

LGTM, nice!

clang/lib/CodeGen/BackendUtil.cpp

 #include "llvm/Transforms/Instrumentation/MemorySanitizer.h"
 #include "llvm/Transforms/Instrumentation/PGOInstrumentation.h"
 #include "llvm/Transforms/Instrumentation/ThreadSanitizer.h"
 #include "llvm/Transforms/ObjCARC.h"
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Scalar/GVN.h"
 #include "llvm/Transforms/Utils.h"
 #include "llvm/Transforms/Utils/CanonicalizeAliases.h"
+#include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
 #include "llvm/Transforms/Utils/NameAnonGlobals.h"
 #include "llvm/Transforms/Utils/SymbolRewriter.h"
 #include <memory>
 using namespace clang;
 using namespace llvm;
 
 namespace {
 
if (CodeGenOpts.OptimizationLevel == 0) {
         MPM.addPass(CanonicalizeAliasesPass());
         MPM.addPass(NameAnonGlobalPass());
       }
     } else {
       // Map our optimization levels into one of the distinct levels used to
       // configure the pipeline.
       PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
 
+      PB.registerPipelineStartEPCallback([](ModulePassManager &MPM) {
+        MPM.addPass(createModuleToFunctionPassAdaptor(
+            EntryExitInstrumenterPass(/*PostInlining=*/false)));
+      });
+
       // Register callbacks to schedule sanitizer passes at the appropriate part of
       // the pipeline.
       // FIXME: either handle asan/the remaining sanitizers or error out
       if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
         PB.registerScalarOptimizerLateEPCallback(
             [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
               FPM.addPass(BoundsCheckingPass());
             });

clang/test/CodeGen/x86_64-instrument-functions.c

 // REQUIRES: x86-registered-target
-// RUN: %clang_cc1 -triple x86_64-unknown-unknown -S -finstrument-functions -O2 -o - %s | FileCheck %s
-// RUN: %clang_cc1 -triple x86_64-unknown-unknown -S -finstrument-functions-after-inlining -O2 -o - %s | FileCheck -check-prefix=NOINLINE %s
+// RUN: %clang_cc1 -fno-experimental-new-pass-manager -triple x86_64-unknown-unknown -S -finstrument-functions -O2 -o - %s | FileCheck %s
+// RUN: %clang_cc1 -fno-experimental-new-pass-manager -triple x86_64-unknown-unknown -S -finstrument-functions-after-inlining -O2 -o - %s | FileCheck -check-prefix=NOINLINE %s
+
+// RUN: %clang_cc1 -fexperimental-new-pass-manager -triple x86_64-unknown-unknown -S -finstrument-functions -O2 -o - %s | FileCheck %s
+// RUN: %clang_cc1 -fexperimental-new-pass-manager -triple x86_64-unknown-unknown -S -finstrument-functions-after-inlining -O2 -o - %s | FileCheck -check-prefix=NOINLINE %s
 
 // It's not so nice having asm tests in Clang, but we need to check that we set
 // up the pipeline correctly in order to have the instrumentation inserted.
 
 int leaf(int x) {
   return x;
 // CHECK-LABEL: leaf:
 // CHECK: callq __cyg_profile_func_enter