Fix LoadOptimizer's handling of load/stores with constant indices for TypedData.

tests/language/vm/load_to_load_unaligned_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.
+// Should be merged into load_to_load_forwarding once Issue 22151 is fixed.
+
+// VMOptions=--optimization-counter-threshold=10
+
+import "package:expect/expect.dart";
+import "dart:typed_data";
+
+testViewAliasing5() {
+  final f32 = new Float32List(2);
+  final raw = f32.buffer.asByteData();
+  f32[0] = 1.5;  // Aliased by unaligned write of the same size.
+  raw.setInt32(1, 0x00400000, Endianness.LITTLE_ENDIAN);
+  return f32[0];
+}
+
+main() {
+  for (var i = 0; i < 20; i++) {
+    Expect.equals(2.0, testViewAliasing5());
+  }
+}