Add support to dart2js for option --enable-asserts.

tests/language/function_type/function_type28_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.
 
 // GENERATED - DON'T EDIT.
 // GENERATED - DON'T EDIT.
 // GENERATED - DON'T EDIT.
 // GENERATED - DON'T EDIT.
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 import 'dart:core';
 import 'dart:core' as core;
 import 'package:expect/expect.dart';
 
 @NoInline()
 @AssumeDynamic()
 confuse(f) => f;
 
-final bool inCheckedMode = (() {
-  bool result = false;
-  assert(result = true);
-  return result;
-})();
-
-typedef F0<T>
-    = int Function(int x1, [List<Function> x2]);
-typedef F1<T>
-    = List<Function> Function([Function x1]);
-typedef F2<T>
-    = List<T> Function(int x0);
-typedef F3<T>
-    = Function(List<T> x0);
-typedef F4<T>
-    = List<T> Function<A>(List<T> x);
-typedef F5<T>
-    = int Function([Function x1]) Function();
-typedef F6<T>
-    = int Function({core.List<core.int> x}) Function();
-typedef F7<T>
-    = Function Function(int y, {int x}) Function();
-typedef F8<T>
-    = Function Function(int x0, [core.List<core.int> x]) Function();
-typedef F9<T>
-    = List<Function> Function(int x0) Function();
-typedef F10<T>
-    = List<Function> Function(int x, [List<Function> x2]) Function();
-typedef F11<T>
-    = List<Function> Function(int y, {List<T> x}) Function();
-typedef F12<T>
-    = core.List<core.int> Function([List<Function> x]) Function();
-typedef F13<T>
-    = core.List<core.int> Function(List<T> x0) Function();
-typedef F14<T>
-    = List<T> Function(int x1, [Function x2]) Function();
-typedef F15<T>
-    = List<T> Function(int x0, {core.List<core.int> x}) Function();
-typedef F16<T>
-    = Function(Function x) Function();
-typedef F17<T>
-    = Function(int y, [core.List<core.int> x]) Function();
-typedef F18<T>
-    = void Function([int x1]) Function();
-typedef F19<T>
-    = void Function({List<Function> x}) Function();
-typedef F20<T>
-    = void Function() Function();
-typedef F21<T>
-    = core.List<core.int> Function<A>(int x) Function();
-typedef F22<T>
-    = A Function<A>(Function x) Function();
-typedef F23<T>
-    = List<T> Function(B x) Function<B extends core.int>();
+typedef F0<T> = int Function(int x1, [List<Function> x2]);
+typedef F1<T> = List<Function> Function([Function x1]);
+typedef F2<T> = List<T> Function(int x0);
+typedef F3<T> = Function(List<T> x0);
+typedef F4<T> = List<T> Function<A>(List<T> x);
+typedef F5<T> = int Function([Function x1]) Function();
+typedef F6<T> = int Function({core.List<core.int> x}) Function();
+typedef F7<T> = Function Function(int y, {int x}) Function();
+typedef F8<T> = Function Function(int x0, [core.List<core.int> x]) Function();
+typedef F9<T> = List<Function> Function(int x0) Function();
+typedef F10<T> = List<Function> Function(int x, [List<Function> x2]) Function();
+typedef F11<T> = List<Function> Function(int y, {List<T> x}) Function();
+typedef F12<T> = core.List<core.int> Function([List<Function> x]) Function();
+typedef F13<T> = core.List<core.int> Function(List<T> x0) Function();
+typedef F14<T> = List<T> Function(int x1, [Function x2]) Function();
+typedef F15<T> = List<T> Function(int x0, {core.List<core.int> x}) Function();
+typedef F16<T> = Function(Function x) Function();
+typedef F17<T> = Function(int y, [core.List<core.int> x]) Function();
+typedef F18<T> = void Function([int x1]) Function();
+typedef F19<T> = void Function({List<Function> x}) Function();
+typedef F20<T> = void Function() Function();
+typedef F21<T> = core.List<core.int> Function<A>(int x) Function();
+typedef F22<T> = A Function<A>(Function x) Function();
+typedef F23<T> = List<T> Function(B x) Function<B extends core.int>();
 
 int f0(int x0, [List<Function> x1]) => null;
 List<Function> f1([Function x0]) => null;
 List<int> f2(int x0) => null;
 f3(List<int> x0) => null;
 List<int> f4<A>(List<int> x) => null;
 int Function([Function x0]) f5() => null;
 int Function({core.List<core.int> x}) f6() => null;
 Function Function(int y, {int x}) f7() => null;
 Function Function(int x0, [core.List<core.int> x]) f8() => null;
@@ skipping 169 matching lines @@
     x2 = confuse(m2);
     l2 = confuse(m2);
     if (!tIsBool) {
       Expect.isTrue(f2 is F2<int>);
       Expect.isFalse(f2 is F2<bool>);
       Expect.isTrue(confuse(f2) is F2<int>);
       Expect.isFalse(confuse(f2) is F2<bool>);
       Expect.equals(tIsDynamic, m2 is F2<bool>);
       Expect.equals(tIsDynamic, confuse(m2) is F2<bool>);
     } else {
-      if (inCheckedMode) {
+      if (typeAssertionsEnabled) {
         Expect.throws(() {
           x2 = (f2 as dynamic);
         });
         Expect.throws(() {
           x2 = confuse(f2);
         });
         List<T> Function(int x0) l2;
         Expect.throws(() {
           l2 = (f2 as dynamic);
         });
@@ skipping 31 matching lines @@
     x3 = confuse(m3);
     l3 = confuse(m3);
     if (!tIsBool) {
       Expect.isTrue(f3 is F3<int>);
       Expect.isFalse(f3 is F3<bool>);
       Expect.isTrue(confuse(f3) is F3<int>);
       Expect.isFalse(confuse(f3) is F3<bool>);
       Expect.equals(tIsDynamic, m3 is F3<bool>);
       Expect.equals(tIsDynamic, confuse(m3) is F3<bool>);
     } else {
-      if (inCheckedMode) {
+      if (typeAssertionsEnabled) {
         Expect.throws(() {
           x3 = (f3 as dynamic);
         });
         Expect.throws(() {
           x3 = confuse(f3);
         });
         Function(List<T> x0) l3;
         Expect.throws(() {
           l3 = (f3 as dynamic);
         });
@@ skipping 31 matching lines @@
     x4 = confuse(m4);
     l4 = confuse(m4);
     if (!tIsBool) {
       Expect.isTrue(f4 is F4<int>);
       Expect.isFalse(f4 is F4<bool>);
       Expect.isTrue(confuse(f4) is F4<int>);
       Expect.isFalse(confuse(f4) is F4<bool>);
       Expect.equals(tIsDynamic, m4 is F4<bool>);
       Expect.equals(tIsDynamic, confuse(m4) is F4<bool>);
     } else {
-      if (inCheckedMode) {
+      if (typeAssertionsEnabled) {
         Expect.throws(() {
           x4 = (f4 as dynamic);
         });
         Expect.throws(() {
           x4 = confuse(f4);
         });
         List<T> Function<A>(List<T> x) l4;
         Expect.throws(() {
           l4 = (f4 as dynamic);
         });
@@ skipping 178 matching lines @@
     x11 = confuse(m11);
     l11 = confuse(m11);
     if (!tIsBool) {
       Expect.isTrue(f11 is F11<int>);
       Expect.isFalse(f11 is F11<bool>);
       Expect.isTrue(confuse(f11) is F11<int>);
       Expect.isFalse(confuse(f11) is F11<bool>);
       Expect.equals(tIsDynamic, m11 is F11<bool>);
       Expect.equals(tIsDynamic, confuse(m11) is F11<bool>);
     } else {
-      if (inCheckedMode) {
+      if (typeAssertionsEnabled) {
         Expect.throws(() {
           x11 = (f11 as dynamic);
         });
         Expect.throws(() {
           x11 = confuse(f11);
         });
         List<Function> Function(int y, {List<T> x}) Function() l11;
         Expect.throws(() {
           l11 = (f11 as dynamic);
         });
@@ skipping 56 matching lines @@
     x13 = confuse(m13);
     l13 = confuse(m13);
     if (!tIsBool) {
       Expect.isTrue(f13 is F13<int>);
       Expect.isFalse(f13 is F13<bool>);
       Expect.isTrue(confuse(f13) is F13<int>);
       Expect.isFalse(confuse(f13) is F13<bool>);
       Expect.equals(tIsDynamic, m13 is F13<bool>);
       Expect.equals(tIsDynamic, confuse(m13) is F13<bool>);
     } else {
-      if (inCheckedMode) {
+      if (typeAssertionsEnabled) {
         Expect.throws(() {
           x13 = (f13 as dynamic);
         });
         Expect.throws(() {
           x13 = confuse(f13);
         });
         core.List<core.int> Function(List<T> x0) Function() l13;
         Expect.throws(() {
           l13 = (f13 as dynamic);
         });
@@ skipping 31 matching lines @@
     x14 = confuse(m14);
     l14 = confuse(m14);
     if (!tIsBool) {
       Expect.isTrue(f14 is F14<int>);
       Expect.isFalse(f14 is F14<bool>);
       Expect.isTrue(confuse(f14) is F14<int>);
       Expect.isFalse(confuse(f14) is F14<bool>);
       Expect.equals(tIsDynamic, m14 is F14<bool>);
       Expect.equals(tIsDynamic, confuse(m14) is F14<bool>);
     } else {
-      if (inCheckedMode) {
+      if (typeAssertionsEnabled) {
         Expect.throws(() {
           x14 = (f14 as dynamic);
         });
         Expect.throws(() {
           x14 = confuse(f14);
         });
         List<T> Function(int x1, [Function x2]) Function() l14;
         Expect.throws(() {
           l14 = (f14 as dynamic);
         });
@@ skipping 32 matching lines @@
     x15 = confuse(m15);
     l15 = confuse(m15);
     if (!tIsBool) {
       Expect.isTrue(f15 is F15<int>);
       Expect.isFalse(f15 is F15<bool>);
       Expect.isTrue(confuse(f15) is F15<int>);
       Expect.isFalse(confuse(f15) is F15<bool>);
       Expect.equals(tIsDynamic, m15 is F15<bool>);
       Expect.equals(tIsDynamic, confuse(m15) is F15<bool>);
     } else {
-      if (inCheckedMode) {
+      if (typeAssertionsEnabled) {
         Expect.throws(() {
           x15 = (f15 as dynamic);
         });
         Expect.throws(() {
           x15 = confuse(f15);
         });
         List<T> Function(int x0, {core.List<core.int> x}) Function() l15;
         Expect.throws(() {
           l15 = (f15 as dynamic);
         });
@@ skipping 199 matching lines @@
     x23 = confuse(m23);
     l23 = confuse(m23);
     if (!tIsBool) {
       Expect.isTrue(f23 is F23<int>);
       Expect.isFalse(f23 is F23<bool>);
       Expect.isTrue(confuse(f23) is F23<int>);
       Expect.isFalse(confuse(f23) is F23<bool>);
       Expect.equals(tIsDynamic, m23 is F23<bool>);
       Expect.equals(tIsDynamic, confuse(m23) is F23<bool>);
     } else {
-      if (inCheckedMode) {
+      if (typeAssertionsEnabled) {
         Expect.throws(() {
           x23 = (f23 as dynamic);
         });
         Expect.throws(() {
           x23 = confuse(f23);
         });
         List<T> Function(B x) Function<B extends core.int>() l23;
         Expect.throws(() {
           l23 = (f23 as dynamic);
         });
         Expect.throws(() {
           l23 = confuse(f23);
         });
       }
       List<T> Function(B x) Function<B extends core.int>() l23 = m23;
       // In checked mode, verifies the type.
       x23 = m23;
       x23 = confuse(m23);
     }
   }
 }
 
 void main() {
   new U28().runTests();
   new U28<int>(tIsInt: true).runTests();
   new U28<bool>(tIsBool: true).runTests();
 }