Run Coverage pass before other *San passes under new pass manager

Summary:
This fixes compiler-rt/test/msan/coverage-levels.cpp under the new pass manager (final check-msan test!).
Under the old pass manager, the coverage pass would run before the MSan pass. The opposite happened under the new pass manager. The MSan pass adds extra basic blocks, changing the number of coverage callbacks.

Reviewers: vitalybuka, leonardchan

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D79698

clang/lib/CodeGen/BackendUtil.cpp

@@ -1002,6 +1002,15 @@ static void addSanitizersAtO0(ModulePassManager &MPM,
                               const Triple &TargetTriple,
                               const LangOptions &LangOpts,
                               const CodeGenOptions &CodeGenOpts) {
+  if (CodeGenOpts.SanitizeCoverageType ||
+      CodeGenOpts.SanitizeCoverageIndirectCalls ||
+      CodeGenOpts.SanitizeCoverageTraceCmp) {
+    auto SancovOpts = getSancovOptsFromCGOpts(CodeGenOpts);
+    MPM.addPass(ModuleSanitizerCoveragePass(
+        SancovOpts, CodeGenOpts.SanitizeCoverageWhitelistFiles,
+        CodeGenOpts.SanitizeCoverageBlacklistFiles));
+  }
+
   auto ASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
     MPM.addPass(RequireAnalysisPass<ASanGlobalsMetadataAnalysis, Module>());
     bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
@@ -1242,6 +1251,17 @@ void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
             EntryExitInstrumenterPass(/*PostInlining=*/false)));
       });
 
+      if (CodeGenOpts.SanitizeCoverageType ||
+          CodeGenOpts.SanitizeCoverageIndirectCalls ||
+          CodeGenOpts.SanitizeCoverageTraceCmp) {
+        PB.registerPipelineStartEPCallback([&](ModulePassManager &MPM) {
+          auto SancovOpts = getSancovOptsFromCGOpts(CodeGenOpts);
+          MPM.addPass(ModuleSanitizerCoveragePass(
+              SancovOpts, CodeGenOpts.SanitizeCoverageWhitelistFiles,
+              CodeGenOpts.SanitizeCoverageBlacklistFiles));
+        });
+      }
+
       // Register callbacks to schedule sanitizer passes at the appropriate part of
       // the pipeline.
       // FIXME: either handle asan/the remaining sanitizers or error out
@@ -1326,15 +1346,6 @@ void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
       }
     }
 
-    if (CodeGenOpts.SanitizeCoverageType ||
-        CodeGenOpts.SanitizeCoverageIndirectCalls ||
-        CodeGenOpts.SanitizeCoverageTraceCmp) {
-      auto SancovOpts = getSancovOptsFromCGOpts(CodeGenOpts);
-      MPM.addPass(ModuleSanitizerCoveragePass(
-          SancovOpts, CodeGenOpts.SanitizeCoverageWhitelistFiles,
-          CodeGenOpts.SanitizeCoverageBlacklistFiles));
-    }
-
     if (LangOpts.Sanitize.has(SanitizerKind::HWAddress)) {
       bool Recover = CodeGenOpts.SanitizeRecover.has(SanitizerKind::HWAddress);
       MPM.addPass(HWAddressSanitizerPass(