ASTImporter: Propagate implicit flag to imported record and field decls

[xazax.hun]

Summary

This patch changes the ASTImporter to propagate the implicit flag to RecordDecls and FieldDecls (to hide the injected type name and anonymous struct/union fields).

If required I could also extend this to all other decl types.

[nrieck]

Ping.

[a.sidorin]

This should be fixed in r269693.

[xazax.hun]

In D6549#662955, @a.sidorin wrote:

This should be fixed in r269693.

Indeed, I commandeer than abandon this revision so it is closed.

lib/AST/ASTImporter.cpp

if (!D2) {
     } else {
       D2 = RecordDecl::Create(Importer.getToContext(), D->getTagKind(),
                               DC, StartLoc, Loc, Name.getAsIdentifierInfo());
     }
     
     D2->setQualifierInfo(Importer.Import(D->getQualifierLoc()));
     D2->setLexicalDeclContext(LexicalDC);
     LexicalDC->addDeclInternal(D2);
+    D2->setImplicit(D->isImplicit());
     if (D->isAnonymousStructOrUnion())
       D2->setAnonymousStructOrUnion(true);
   }
   
   Importer.Imported(D, D2);
 
   if (D->isCompleteDefinition() && ImportDefinition(D, D2, IDK_Default))
     return nullptr;
IndirectFieldDecl *ToIndirectField = IndirectFieldDecl::Create(
       Importer.getToContext(), DC, Loc, Name.getAsIdentifierInfo(), T,
       NamedChain, D->getChainingSize());
 
   for (const auto *Attr : D->attrs())
     ToIndirectField->addAttr(Attr->clone(Importer.getToContext()));
 
   ToIndirectField->setAccess(D->getAccess());
   ToIndirectField->setLexicalDeclContext(LexicalDC);
+  ToIndirectField->setImplicit(D->isImplicit());
   Importer.Imported(D, ToIndirectField);
   LexicalDC->addDeclInternal(ToIndirectField);
   return ToIndirectField;
 }
 
 Decl *ASTNodeImporter::VisitObjCIvarDecl(ObjCIvarDecl *D) {
   // Import the major distinguishing characteristics of an ivar.
   DeclContext *DC, *LexicalDC;