Support call methods on functions

test/codegen/language/call_function_test.dart

+// 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.
+
+import "package:expect/expect.dart";
+
+Object bar(Object x) { return x; }
+
+Function baz = bar;
+
+dynamic dyn = bar;
+
+class Foo {
+  Object call(Object x) { return 'Foo$x'; }
+}
+
+typedef Object FooType(Object x);
+FooType foo = bar;
+
+void main() {
+  Expect.equals(42, bar.call(42));
+  Expect.equals(42, baz.call(42));
+  Expect.equals(42, foo.call(42));
+  Expect.equals(42, dyn.call(42));
+  Expect.equals(42, bar(42));
+  Expect.equals(42, baz(42));
+  Expect.equals(42, foo(42));
+  Expect.equals(42, dyn(42));
+
+  baz = new Foo();
+  foo = new Foo();
+  dyn = new Foo();
+  Expect.equals('Foo42', baz.call(42));
+  Expect.equals('Foo42', foo.call(42));
+  Expect.equals('Foo42', dyn.call(42));
+  Expect.equals('Foo42', baz(42));
+  Expect.equals('Foo42', foo(42));
+  Expect.equals('Foo42', dyn(42));
+}