Fix http://code.google.com/p/dart/issues/detail?id=13007 by introducing a new Marker value in the S…

tests/compiler/dart2js/value_range_test.dart

 // Copyright (c) 2012, 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.
 
 import "package:expect/expect.dart";
 import 'compiler_helper.dart';
 
 const int REMOVED = 0;
 const int ABOVE_ZERO = 1;
 const int BELOW_LENGTH = 2;
 const int KEPT = 3;
 const int ONE_CHECK = 4;
 const int ONE_ZERO_CHECK = 5;
+const int BELOW_ZERO_CHECK = 6;
 
 final List TESTS = [
 """
 main() {
   var a = new List();
   var sum = 0;
   for (int i = 0; i < a.length; i++) {
     sum += a[i];
   }
   return sum;
@@ skipping 166 matching lines @@
   // want an int.
   int sum = ~value;
   for (int i = 0; i < 42; i++) sum += (value & 4);
   var a = new List();
   if (value >= a.length) return;
   if (value <= -1) return;
   return a[value];
 }
 """,
 REMOVED,
+"""
+main(value) {
+  var a = new List(4);
+  var sum = 0;
+  for (int i = 0; i < a.length; i++) {
+    sum += a[i];
+    if (sum == 0) i++;
+  }
+  return sum;
+}
+""",
+REMOVED,
+"""
+main(value) {
+  var a = new List(5);
+  var sum = 0;
+  for (int i = a.length - 1; i >= 0; i--) {
+    sum += a[i];
+    if (sum == 0) i--;
+  }
+  return sum;
+}
+""",
+REMOVED,
+"""
+main(value) {
+  var a = new List(6);
+  var sum = 0;
+  for (int i = 0; i < a.length; i++) {
+    sum += a[i];
+    if (sum == 0) i--;
+  }
+  return sum;
+}
+""",
+BELOW_ZERO_CHECK,
+"""
+main(value) {
+  var a = new List(7);
+  var sum = 0;
+  for (int i = 0; i < a.length;) {
+    sum += a[i];
+    sum == 0 ? i-- : i++;
+  }
+  return sum;
+}
+""",
+BELOW_ZERO_CHECK,
 ];
 
 // TODO(ahe): It would probably be better if this test used the real
 // core library sources, as its purpose is to detect failure to
 // optimize fixed-sized arrays.
 const String DEFAULT_CORELIB_WITH_LIST_INTERFACE = r'''
   print(var obj) {}
   abstract class num {}
   abstract class int extends num { }
   abstract class double extends num { }
@@ skipping 73 matching lines @@
       coreSource: DEFAULT_CORELIB_WITH_LIST_INTERFACE,
       interceptorsSource: INTERCEPTORSLIB_WITH_MEMBERS);
   switch (kind) {
     case REMOVED:
       Expect.isTrue(!generated.contains('ioore'));
       break;
 
     case ABOVE_ZERO:
       Expect.isTrue(!generated.contains('< 0'));
       Expect.isTrue(generated.contains('ioore'));
+      break;
+
+    case BELOW_ZERO_CHECK:
+      Expect.isTrue(generated.contains('< 0'));
+      Expect.isTrue(!generated.contains('||'));
       Expect.isTrue(generated.contains('ioore'));
       break;
 
     case BELOW_LENGTH:
       Expect.isTrue(!generated.contains('||'));
       Expect.isTrue(generated.contains('ioore'));
       break;
 
     case KEPT:
       Expect.isTrue(generated.contains('ioore'));
@@ skipping 12 matching lines @@
       break;
   }
 }
 
 
 main() {
   for (int i = 0; i < TESTS.length;  i += 2) {
     expect(TESTS[i], TESTS[i + 1]);
   }
 }