Fix crash in optimized code caused by missing IC data.

tests/language/optimized_isempty_test.dart

+// Copyright (c) 2013, 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.
+// VMOptions=--optimization-counter-threshold=10 --no-use-osr
+
+// Test optimization and polymorphic inlining of String.isEmpty.
+
+import "package:expect/expect.dart";
+
+test(s) => s.isEmpty;
+
+main() {
+  var x = "abc";
+  var y = [123, 12345, 765];
+  Expect.equals(false, test(x));
+  Expect.equals(false, test(y));
+  for (var i=0; i<20; i++) test(x);
+  Expect.equals(false, test(x));
+  Expect.equals(false, test(y));
+}
+