Fix <rdar://problem/6450964> clang on xcode: Assertion failed: (RecordForDecl && "lookupFieldDeclForIvar no storage for class").

This was a recent regression caused by r61043 (related to code gen. for ivar references).

Fariborz, please review. I have some other concerns related to code generation for ivars that we can discuss later.

llvm-svn: 61134

clang/lib/AST/DeclObjC.cpp

@@ -369,6 +369,8 @@ void ObjCInterfaceDecl::addInstanceVariablesToClass(ObjCIvarDecl **ivars,
 ///
 FieldDecl *ObjCInterfaceDecl::lookupFieldDeclForIvar(ASTContext &Context, 
                                                      const ObjCIvarDecl *ivar) {
+  if (!RecordForDecl)
+    addRecordToClass(Context);
   assert(RecordForDecl && "lookupFieldDeclForIvar no storage for class");
   DeclarationName Member = ivar->getDeclName();
   DeclContext::lookup_result Lookup = RecordForDecl->lookup(Context, Member);

clang/test/SemaObjC/interface-layout-2.m

@@ -0,0 +1,16 @@
+// RUN: clang %s -fsyntax-only -verify
+@interface A
+{
+  int ivar;
+}
+@end
+
+@interface B : A
+- (int)ivar;
+@end
+
+@implementation B
+- (int)ivar {
+  return ivar;
+} 
+@end