Get gcc to check that we don't ignore return values of functions that can...

src/parser.cc

Index: src/parser.cc
===================================================================
--- src/parser.cc	(revision 5365)
+++ src/parser.cc	(working copy)
@@ -4282,7 +4282,11 @@
   for (int i = 0; i < argc; i++) {
     Handle<Object> element = arguments[i];
     if (!element.is_null()) {
-      array->SetFastElement(i, *element);
+      Object* ok = array->SetFastElement(i, *element);
+      USE(ok);  // Don't get an unused variable warning.
+      // We know this doesn't cause a GC here because we allocated the JSArray
+      // large enough.
+      ASSERT(!ok->IsFailure());
     }
   }
   ZoneList<Expression*>* args = new ZoneList<Expression*>(2);