Fix gcstress test failure

test/mjsunit/getters-on-elements.js

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
 //       with the distribution.
 //     * Neither the name of Google Inc. nor the names of its
 //       contributors may be used to endorse or promote products derived
 //       from this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // Flags: --allow-natives-syntax --max-opt-count=100 --noalways-opt
+// Flags: --nocollect-maps
 
 // We specify max-opt-count because we opt/deopt the same function many
 // times.
 
+// We specify nocollect-maps because in gcstress we can end up deoptimizing
+// a function in a gc in the stack guard at the beginning of the (optimized)
+// function due to leftover map clearing work that results in deoptimizing
+// dependent code from those maps. The choice is to insert strategic gc()
+// calls or specify this flag.
+
 // It's nice to run this in other browsers too.
 var standalone = false;
 if (standalone) {
   assertTrue = function(val) {
     if (val != true) {
       print("FAILURE");
     }
   }
 
   assertFalse = function(val) {
@@ skipping 162 matching lines @@
 optimize(fun);
 fun(a);
 assertOptimized(fun);
 
 var calls = 0;
 delete a[0];
 ap.__defineGetter__(0, function() { calls++; return 0; });
 fun(a);
 assertEquals(1, calls);
 assertUnoptimized(fun);