dart2js: Trust type annotations more often with --trust-type-annotation.

pkg/compiler/lib/src/ssa/codegen.dart

 // Copyright (c) 2012, 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.
 
 part of ssa;
 
 class SsaCodeGeneratorTask extends CompilerTask {
 
   final JavaScriptBackend backend;
 
@@ skipping 2554 matching lines @@
     } else {
       compiler.internalError(input, 'Unexpected check.');
     }
     return test;
   }
 
   void visitTypeConversion(HTypeConversion node) {
     if (node.isArgumentTypeCheck || node.isReceiverTypeCheck) {
       ClassWorld classWorld = compiler.world;
       // An int check if the input is not int or null, is not
-      // sufficient for doing a argument or receiver check.
-      assert(!node.checkedType.containsOnlyInt(classWorld) ||
+      // sufficient for doing an argument or receiver check.
+      assert(compiler.trustTypeAnnotations ||
+             !node.checkedType.containsOnlyInt(classWorld) ||
              node.checkedInput.isIntegerOrNull(compiler));
       js.Expression test = generateTest(node.checkedInput, node.checkedType);
       js.Block oldContainer = currentContainer;
       js.Statement body = new js.Block.empty();
       currentContainer = body;
       if (node.isArgumentTypeCheck) {
         generateThrowWithHelper('iae', node.checkedInput);
       } else if (node.isReceiverTypeCheck) {
         use(node.checkedInput);
         String methodName =
@@ skipping 135 matching lines @@
   js.PropertyAccess accessHelper(String name) {
     Element helper = backend.findHelper(name);
     if (helper == null) {
       // For mocked-up tests.
       return js.js('(void 0).$name');
     }
     registry.registerStaticUse(helper);
     return backend.namer.elementAccess(helper);
   }
 }