Revert "[C++20] [Modules] Handle initializer for Header Units"

This reverts commit db6152a.

This commit fails in ppc64. Since we want to backport it to 15.x. So
revert it now to keep the patch complete.

Author: ChuanqiXu9

clang/lib/CodeGen/CGDeclCXX.cpp

@@ -650,8 +650,8 @@ void CodeGenModule::EmitCXXModuleInitFunc(Module *Primary) {
 
   SmallVector<llvm::Function *, 8> ModuleInits;
   for (Module *M : AllImports) {
-    // No Itanium initializer in header like modules.
-    if (M->isHeaderLikeModule())
+    // No Itanium initializer in module map modules.
+    if (M->isModuleMapModule())
       continue; // TODO: warn of mixed use of module map modules and C++20?
     llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
     SmallString<256> FnName;
@@ -779,8 +779,8 @@ CodeGenModule::EmitCXXGlobalInitFunc() {
   SmallVector<llvm::Function *, 8> ModuleInits;
   if (CXX20ModuleInits)
     for (Module *M : ImportedModules) {
-      // No Itanium initializer in header like modules.
-      if (M->isHeaderLikeModule())
+      // No Itanium initializer in module map modules.
+      if (M->isModuleMapModule())
         continue;
       llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
       SmallString<256> FnName;

clang/lib/CodeGen/CodeGenModule.cpp

@@ -521,7 +521,7 @@ static void setVisibilityFromDLLStorageClass(const clang::LangOptions &LO,
 
 void CodeGenModule::Release() {
   Module *Primary = getContext().getModuleForCodeGen();
-  if (CXX20ModuleInits && Primary && !Primary->isHeaderLikeModule())
+  if (CXX20ModuleInits && Primary && !Primary->isModuleMapModule())
     EmitModuleInitializers(Primary);
   EmitDeferred();
   DeferredDecls.insert(EmittedDeferredDecls.begin(),
@@ -2521,23 +2521,21 @@ void CodeGenModule::EmitModuleInitializers(clang::Module *Primary) {
   // source, first Global Module Fragments, if present.
   if (auto GMF = Primary->getGlobalModuleFragment()) {
     for (Decl *D : getContext().getModuleInitializers(GMF)) {
-      if (isa<ImportDecl>(D))
-        continue;
-      assert(isa<VarDecl>(D) && "GMF initializer decl is not a var?");
+      assert(D->getKind() == Decl::Var && "GMF initializer decl is not a var?");
       EmitTopLevelDecl(D);
     }
   }
   // Second any associated with the module, itself.
   for (Decl *D : getContext().getModuleInitializers(Primary)) {
     // Skip import decls, the inits for those are called explicitly.
-    if (isa<ImportDecl>(D))
+    if (D->getKind() == Decl::Import)
       continue;
     EmitTopLevelDecl(D);
   }
   // Third any associated with the Privat eMOdule Fragment, if present.
   if (auto PMF = Primary->getPrivateModuleFragment()) {
     for (Decl *D : getContext().getModuleInitializers(PMF)) {
-      assert(isa<VarDecl>(D) && "PMF initializer decl is not a var?");
+      assert(D->getKind() == Decl::Var && "PMF initializer decl is not a var?");
       EmitTopLevelDecl(D);
     }
   }