Fix rti encoding of generic methods

tests/language/generic_method_types_test.dart

+// Copyright (c) 2016, 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.
+
+import 'package:expect/expect.dart';
+
+typedef O Convert<I, O>(I input);
+typedef Other(a, b);
+
+class Mixin<E> {
+  E convert1<I>(I input) => null;
+}
+
+class Class<F> extends Object with Mixin<F> {
+  O convert2<O>(F input) => null;
+}
+
+O convert<I, O>(I input) => null;
+
+test1() {
+  var val = new Class<String>();
+  Expect.isTrue(val.convert1 is Convert);
+  Expect.isTrue(val.convert1 is Convert<String, String>);
+  Expect.isTrue(val.convert1 is Convert<int, String>);
+  Expect.isFalse(val.convert1 is Convert<String, int>);
+  Expect.isFalse(val.convert1 is Other);
+}
+
+test2() {
+  var val = new Class<String>();
+  Expect.isTrue(val.convert2 is Convert);
+  Expect.isTrue(val.convert2 is Convert<String, String>);
+  Expect.isTrue(val.convert2 is Convert<String, int>);
+  Expect.isFalse(val.convert2 is Convert<int, String>);
+  Expect.isFalse(val.convert2 is Other);
+}
+
+test3() {
+  Expect.isTrue(convert is Convert);
+  Expect.isTrue(convert is Convert<String, String>);
+  Expect.isTrue(convert is Convert<String, int>);
+  Expect.isTrue(convert is Convert<int, String>);
+  Expect.isFalse(convert is Other);
+}
+
+main() {
+  test1(); /// 01: ok
+  test2(); /// 02: ok
+  test3(); /// 03: ok
+}