Implement Obj-C ivar references to aggregates.

Implement Obj-C lvalue message sends (aggregate returns).

Update several places to emit more precise ErrorUnsupported warnings
  for currently unimplemented Obj-C features (main missing chunks are
  property references, Obj-C exception handling, and the for ... in
  syntax).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@55234 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExprAgg.cpp b/lib/CodeGen/CGExprAgg.cpp
index bc6af12..fbba9c6 100644
--- a/lib/CodeGen/CGExprAgg.cpp
+++ b/lib/CodeGen/CGExprAgg.cpp
@@ -88,7 +88,13 @@
   void VisitBinComma(const BinaryOperator *E);
 
   void VisitObjCMessageExpr(ObjCMessageExpr *E);
-
+  void VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
+    EmitAggLoadOfLValue(E);
+  }
+  void VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
+    // FIXME: Implement!
+    CGF.ErrorUnsupported(E, "aggregate expression (Objective-C property reference)");
+  }
   
   void VisitConditionalOperator(const ConditionalOperator *CO);
   void VisitInitListExpr(InitListExpr *E);