objc - fix up the builtin type for objc_assign_ivar.
// rdar://9362887.

llvm-svn: 138412
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 1b2c5cf..75a573e 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -6140,7 +6140,11 @@
     assert(!RequiresICE && "Can't require complex ICE");
     Type = Context.getComplexType(ElementType);
     break;
-  }      
+  }  
+  case 'Y' : {
+    Type = Context.getPointerDiffType();
+    break;
+  }
   case 'P':
     Type = Context.getFILEType();
     if (Type.isNull()) {