dart2js ssa: Open coding of removeLast should use -1 as index

tests/compiler/dart2js_extra/js_array_removeLast_error_test.dart

Index: tests/compiler/dart2js_extra/js_array_removeLast_error_test.dart
diff --git a/tests/compiler/dart2js_extra/js_array_removeLast_error_test.dart b/tests/compiler/dart2js_extra/js_array_removeLast_error_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..6fc14dce16f8cbae9c59086f64e29b17c88a65f2
--- /dev/null
+++ b/tests/compiler/dart2js_extra/js_array_removeLast_error_test.dart
@@ -0,0 +1,39 @@
+// Copyright (c) 2015, 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 that optimized JSArray removeLast() calls generate the same error as
+// dyncamically dispatched calls.
+
+import 'package:expect/expect.dart';
+
+@NoInline() @AssumeDynamic()
+confuse(x) => x;
+
+
+Error getError(action()) {
+  try {
+    action();
+    Expect.fail('must throw');
+  } catch (e) {
+    return e;
+  }
+}
+
+main() {
+  fault1() {
+    return confuse([]).removeLast();
+  }
+
+  fault2() {
+    var a = [];
+    while (confuse(false)) a.add(1);
+    // This one should be optimized since [a] is a growable JSArray.
+    return a.removeLast();
+  }
+
+  var e1 = getError(fault1);
+  var e2 = getError(fault2);
+
+  Expect.equals('$e1', '$e2');
+}