Reimplement HandleInvalidTagDeclDefinition without clang support.

See https://reviews.llvm.org/D92248

Author: vgvassilev

interpreter/cling/lib/Interpreter/DeclCollector.cpp

@@ -263,24 +263,16 @@ namespace cling {
     Transaction::DelayCallInfo DCI(DeclGroupRef(TD),
                                    Transaction::kCCIHandleTagDeclDefinition);
     m_CurTransaction->append(DCI);
+    if (TD->isInvalidDecl()) {
+       m_CurTransaction->setIssuedDiags(Transaction::kErrors);
+       return;
+    }
     if (m_Consumer
         && (!comesFromASTReader(DeclGroupRef(TD))
             || !shouldIgnore(TD)))
       m_Consumer->HandleTagDeclDefinition(TD);
   }
 
-  void DeclCollector::HandleInvalidTagDeclDefinition(clang::TagDecl *TD){
-    assertHasTransaction(m_CurTransaction);
-    Transaction::DelayCallInfo DCI(DeclGroupRef(TD),
-                                   Transaction::kCCIHandleTagDeclDefinition);
-    m_CurTransaction->append(DCI);
-    m_CurTransaction->setIssuedDiags(Transaction::kErrors);
-    if (m_Consumer
-        && (!comesFromASTReader(DeclGroupRef(TD))
-            || !shouldIgnore(TD)))
-      m_Consumer->HandleInvalidTagDeclDefinition(TD);
-  }
-
   void DeclCollector::HandleVTable(CXXRecordDecl* RD) {
     assertHasTransaction(m_CurTransaction);
     Transaction::DelayCallInfo DCI(DeclGroupRef(RD),

interpreter/cling/lib/Interpreter/DeclCollector.h

@@ -96,7 +96,6 @@ namespace cling {
     bool HandleTopLevelDecl(clang::DeclGroupRef DGR) final;
     void HandleInterestingDecl(clang::DeclGroupRef DGR) final;
     void HandleTagDeclDefinition(clang::TagDecl* TD) final;
-    void HandleInvalidTagDeclDefinition(clang::TagDecl* TD) final;
     void HandleVTable(clang::CXXRecordDecl* RD) final;
     void CompleteTentativeDefinition(clang::VarDecl* VD) final;
     void HandleTranslationUnit(clang::ASTContext& Ctx) final;

interpreter/llvm/src/tools/clang/lib/Sema/SemaTemplateInstantiate.cpp

@@ -2235,19 +2235,13 @@ Sema::InstantiateClass(SourceLocation PointOfInstantiation,
   // Exit the scope of this instantiation.
   SavedContext.pop();
 
-  if (!Instantiation->isInvalidDecl()) {
-    Consumer.HandleTagDeclDefinition(Instantiation);
-
-    // Always emit the vtable for an explicit instantiation definition
-    // of a polymorphic class template specialization. Otherwise, eagerly
-    // instantiate only constexpr virtual functions in preparation for their use
-    // in constant evaluation.
-    if (TSK == TSK_ExplicitInstantiationDefinition)
-      MarkVTableUsed(PointOfInstantiation, Instantiation, true);
-    else if (MightHaveConstexprVirtualFunctions)
-      MarkVirtualMembersReferenced(PointOfInstantiation, Instantiation,
-                                   /*ConstexprOnly*/ true);
-  }
+  Consumer.HandleTagDeclDefinition(Instantiation);
+
+  // Always emit the vtable for an explicit instantiation definition
+  // of a polymorphic class template specialization.
+  if (!Instantiation->isInvalidDecl() &&
+      TSK == TSK_ExplicitInstantiationDefinition)
+    MarkVTableUsed(PointOfInstantiation, Instantiation, true);
 
   return Instantiation->isInvalidDecl();
 }