Correct and GC unrecognized flags from our tests.

tests/language/vm/regress_16873_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--new_gen_heap_size=1 --no_inline_alloc
+// VMOptions=--new_gen_semi_max_size=1 --no_inline_alloc
 
 // Regression test for slow-path allocation in the allocation stub.
 
 library map_test;
 import 'dart:collection';
 
 void testCollection(var collection, n) {
   for (int i = 0; i < n; i++) {
     if (i % 1000 == 0) print(i);
     collection.add(i);
   }
 }
 
 main() {
   const int N = 100000;
   testCollection(new LinkedHashSet(), N);
 }