Improve aliasing info for load elimination of array loads.

tests/language/vm/load_to_load_forwarding_vm_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.
 // Test correctness of side effects tracking used by load to load forwarding.
 
 // VMOptions=--optimization-counter-threshold=10
 
 import "package:expect/expect.dart";
 import "dart:typed_data";
 
@@ skipping 194 matching lines @@
   }
   var v;
   if (f) {
     v = arr[0];
   } else {
     v = arr[0];
   }
   return v + w;
 }
 
+testIndexedNoAlias(a) {
+  a[0] = 1;
+  a[1] = 2;
+  a[2] = 3;
+  return a[0] + a[1];
+}
+
+testIndexedAliasedStore(a, b) {
+  a[0] = 1;
+  a[1] = 2;
+  if (a == b) {
+    b[0] = 3;
+  }
+  return a[0] + a[1];
+}
+
+testIndexedAliasedStore1(a, b) {
+  a[0] = 1;
+  a[1] = 2;
+  if (a == b) {
+    b[0] = 3;
+  }
+  return a[0] + a[1];
+}
+
+testIndexedAliasedStore2(a, b, i) {
+  a[0] = 1;
+  a[1] = 2;
+  if (a == b) {
+    b[i] = 3;
+  }
+  return a[0] + a[1];
+}
+var indices = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
 
 main() {
   final fixed = new List(10);
   final growable = [];
   testImmutableVMFields(fixed, true);
   testImmutableVMFields(growable, false);
   testImmutableVMFields(growable, false);
 
   final f64List = new Float64List(2);
   testPhiRepresentation(true, f64List);
@@ skipping 31 matching lines @@
 
   for (var i = 0; i < 20; i++) {
     Expect.equals(0.0, testPhiMultipleRepresentations(true, f64List));
     Expect.equals(0, testPhiMultipleRepresentations(false, const [1,2]));
   }
 
   final escape = new List(1);
   for (var i = 0; i < 20; i++) {
     fakeAliasing(escape);
   }
+
+  final array = new List(3);
+  for (var i = 0; i < 20; i++) {
+    Expect.equals(3, testIndexedNoAlias(array));
+  }
+  for (var i = 0; i < 20; i++) {
+    Expect.equals(5, testIndexedAliasedStore1(array, array));
+  }
+  for (var i = 0; i < 20; i++) {
+    Expect.equals(4, testIndexedAliasedStore2(array, array, indices[1]));
+  }
 }