Fix 11574: Smi is a subtype of parametrizable Compare.

tests/language/smi_type_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=8
+
+import "package:expect/expect.dart";
+
+main() {
+  // Make instance-of polymorphic.
+  isNum([]);
+  isNumRaw([]);
+  isNotNum([]);
+  isNotInt([]);
+  for (int i = 0; i < 20; i++) {
+    Expect.isTrue(isNum(i));
+    Expect.isTrue(isNumRaw(i));
+    Expect.isFalse(isNotNum(i));
+    Expect.isFalse(isNotInt(i));
+  }
+}
+
+isNum(a) {
+  return a is Comparable<num>;
+}
+
+isNumRaw(a) {
+  return a is Comparable;
+}
+
+isNotNum(a) {
+  return a is Comparable<String>;
+}
+
+isNotInt(a) {
+  return a is Comparable<double>;
+}