Fix clang build after r12956

That change added a test which called the handlified version of JSObject::SetElement and didn't check the return value, but that method has a MUST_USE_RESULT annotation. This change removes the annotation for consistency with other handlified static methods (like SetProperty).

Review URL: https://chromiumcodereview.appspot.com/11359212
Patch from Adam Klein <adamk@chromium.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12963 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/objects.h

@@ -1880,7 +1880,7 @@ class JSObject: public JSReceiver {
                                       StrictModeFlag strict_mode);
 
   // Empty handle is returned if the element cannot be set to the given value.
-  static MUST_USE_RESULT Handle<Object> SetElement(
+  static Handle<Object> SetElement(
       Handle<JSObject> object,
       uint32_t index,
       Handle<Object> value,