Enable default @synthesize by default.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@152140 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/ToolChains.h b/lib/Driver/ToolChains.h
index aee2174..e894105 100644
--- a/lib/Driver/ToolChains.h
+++ b/lib/Driver/ToolChains.h
@@ -349,7 +349,7 @@
   }
   
   virtual bool IsObjCDefaultSynthPropertiesDefault() const {
-    return false;
+    return true;
   }
 
   virtual bool IsObjCNonFragileABIDefault() const {