Revert "Support runtime check of function types."

tests/language/function_subtype0_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.
-// Dart test program for constructors and initializers.
-
-// Check function subtyping.
-
-import 'package:expect/expect.dart';
-
-typedef t__();
-typedef void t_void_();
-typedef void t_void_2();
-typedef int t_int_();
-typedef int t_int_2();
-typedef Object t_Object_();
-typedef double t_double_();
-typedef void t_void__int(int i);
-typedef int t_int__int(int i);
-typedef int t_int__int2(int i);
-typedef int t_int__Object(Object o);
-typedef Object t_Object__int(int i);
-typedef int t_int__double(double d);
-typedef int t_int__int_int(int i1, int i2);
-typedef void t_inline_void_(void f());
-typedef void t_inline_void__int(void f(int i));
-
-void _() => null;
-void void_() {}
-void void_2() {}
-int int_() => 0;
-int int_2() => 0;
-Object Object_() => null;
-double double_() => 0.0;
-void void__int(int i) {}
-int int__int(int i) => 0;
-int int__int2(int i) => 0;
-int int__Object(Object o) => 0;
-Object Object__int(int i) => null;
-int int__double(double d) => 0;
-int int__int_int(int i1, int i2) => 0;
-void inline_void_(void f()) {}
-void inline_void__int(void f(int i)) {}
-
-main() {
-  // () -> int <: Function
-  Expect.isTrue(int_ is Function);
-  // () -> dynamic <: () -> dynamic
-  Expect.isTrue(_ is t__);
-  // () -> dynamic <: () -> void
-  Expect.isTrue(_ is t_void_);
-  // () -> void <: () -> dynamic
-  Expect.isTrue(void_ is t__);
-  // () -> int <: () -> void
-  Expect.isTrue(int_ is t_void_);
-  // () -> void <: () -> int
-  Expect.isFalse(void_ is t_int_);
-  // () -> void <: () -> void
-  Expect.isTrue(void_ is t_void_2);
-  // () -> int <: () -> int
-  Expect.isTrue(int_ is t_int_2);
-  // () -> int <: () -> Object
-  Expect.isTrue(int_ is t_Object_);
-  // () -> int <: () -> double
-  Expect.isFalse(int_ is t_double_);
-  // () -> int <: (int) -> void
-  Expect.isFalse(int_ is t_void__int);
-  // () -> void <: (int) -> int
-  Expect.isFalse(void_ is t_int__int);
-  // () -> void <: (int) -> void
-  Expect.isFalse(void_ is t_void__int);
-  // (int) -> int <: (int) -> int
-  Expect.isTrue(int__int is t_int__int2);
-  // (Object) -> int <: (int) -> Object
-  Expect.isTrue(int__Object is t_Object__int);
-  // (int) -> int <: (double) -> int
-  Expect.isFalse(int__int is t_int__double);
-  // () -> int <: (int) -> int
-  Expect.isFalse(int_ is t_int__int);
-  // (int) -> int <: (int,int) -> int
-  Expect.isFalse(int__int is t_int__int_int);
-  // (int,int) -> int <: (int) -> int
-  Expect.isFalse(int__int_int is t_int__int);
-  // (()->void) -> void <: ((int)->void) -> void
-  Expect.isFalse(inline_void_ is t_inline_void__int);
-  // ((int)->void) -> void <: (()->void) -> void
-  Expect.isFalse(inline_void__int is t_inline_void_);
-}