Adds tests for syntactic support for generic methods.

tests/language/generic_sends_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.
+
+// Dart test verifying that the parser can handle certain cases where
+// grammar ambiguity is resolved in favor of generic sends, not
+// relational expressions.
+
+f(arg1, [arg2]) => null;
+g<X, Y>(arg) => null;
+
+main() {
+  // Generic invocations.
+  f(g<int, String>(3));
+  f(g<int, List<String>>(3));
+  f(g<int, String>(3), 4);
+  f(g<int, List<String>>(3), 4);
+
+  // Relational expressions.
+  int a = 0, b = 1, c = 2, d = 3;
+  f(a < b, c > 3);
+  f(a < b, c >> 3);
+  f(a < b, c < d >> 3);
+}