Revert 374481 "[tsan,msan] Insert module constructors in a module pass"

CodeGen/sanitizer-module-constructor.c fails on mac and windows, see e.g.
http://lab.llvm.org:8011/builders/clang-x64-windows-msvc/builds/11424

llvm-svn: 374503
diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 75a54d8..469aa0c 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -974,7 +974,6 @@
   }
 
   if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
-    MPM.addPass(MemorySanitizerPass({}));
     MPM.addPass(createModuleToFunctionPassAdaptor(MemorySanitizerPass({})));
   }
 
@@ -984,7 +983,6 @@
   }
 
   if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
-    MPM.addPass(ThreadSanitizerPass());
     MPM.addPass(createModuleToFunctionPassAdaptor(ThreadSanitizerPass()));
   }
 }
@@ -1164,23 +1162,16 @@
             [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
               FPM.addPass(BoundsCheckingPass());
             });
-      if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
-        PB.registerPipelineStartEPCallback([](ModulePassManager &MPM) {
-          MPM.addPass(MemorySanitizerPass({}));
-        });
+      if (LangOpts.Sanitize.has(SanitizerKind::Memory))
         PB.registerOptimizerLastEPCallback(
             [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
               FPM.addPass(MemorySanitizerPass({}));
             });
-      }
-      if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
-        PB.registerPipelineStartEPCallback(
-            [](ModulePassManager &MPM) { MPM.addPass(ThreadSanitizerPass()); });
+      if (LangOpts.Sanitize.has(SanitizerKind::Thread))
         PB.registerOptimizerLastEPCallback(
             [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
               FPM.addPass(ThreadSanitizerPass());
             });
-      }
       if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
         PB.registerPipelineStartEPCallback([&](ModulePassManager &MPM) {
           MPM.addPass(