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

Index: tests/compiler/dart2js/value_range_test.dart
===================================================================
--- tests/compiler/dart2js/value_range_test.dart	(revision 27195)
+++ tests/compiler/dart2js/value_range_test.dart	(working copy)
@@ -11,6 +11,7 @@
 const int KEPT = 3;
 const int ONE_CHECK = 4;
 const int ONE_ZERO_CHECK = 5;
+const int BELOW_ZERO_CHECK = 6;
 
 final List TESTS = [
 """
@@ -197,6 +198,54 @@
 }
 """,
 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
@@ -290,6 +339,11 @@
     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;