[test] Properly disable test that doesn't work in GC stress.

test/mjsunit/regress/regress-crbug-500497.js

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // New space must be at max capacity to trigger pretenuring decision.
 // Flags: --allow-natives-syntax --verify-heap --max-semi-space-size=1
 
 var global = [];  // Used to keep some objects alive.
 
 function Ctor() {
   var result = {a: {}, b: {}, c: {}, d: {}, e: {}, f: {}, g: {}};
   return result;
 }
 
 for (var i = 0; i < 120; i++) {
-  // This print() is important! Without it, in --gc-stress mode, the function
-  // Ctor is optimized too early. No idea why.
-  print(i);
   // Make the "a" property long-lived, while everything else is short-lived.
   global.push(Ctor().a);
   (function FillNewSpace() { new Array(10000); })();
 }
 
 // The bad situation is only triggered if Ctor wasn't optimized too early.
 assertUnoptimized(Ctor);
 // Optimized code for Ctor will pretenure the "a" property, so it will have
 // three allocations:
 // #1 Allocate the "result" object in new-space.
 // #2 Allocate the object stored in the "a" property in old-space.
 // #3 Allocate the objects for the "b" through "g" properties in new-space.
 %OptimizeFunctionOnNextCall(Ctor);
 for (var i = 0; i < 10000; i++) {
   // At least one of these calls will run out of new space. The bug is
   // triggered when it is allocation #3 that triggers GC.
   Ctor();
 }