fix #30094, assert should work with a function

pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.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.
 
 /// This library defines runtime operations on objects used by the code
 /// generator.
 part of dart._runtime;
 
 class InvocationImpl extends Invocation {
   final Symbol memberName;
@@ skipping 683 matching lines @@
     }
   } else if (typeof $values === 'object') {
     for (let key of $getOwnPropertyNames($values)) {
       map._set(key, $values[key]);
     }
   }
   return map;
 })()''');
 
 @JSExportName('assert')
-assert_(condition, [message]) => JS(
-    '',
-    '''(() => {
-  if (!$condition) $throwAssertionError(message);
-})()''');
+assert_(condition, message) {
+  if (JS('bool', '!#', condition)) throwAssertionError(message);

[vsm, 2017/07/07 12:38:47]

If the static type of condition is `dynamic`, we would need to test for a
function at runtime, right?

+}
 
 /// Store a JS error for an exception.  For non-primitives, we store as an
 /// expando.  For primitive, we use a side cache.  To limit memory leakage, we
 /// only keep the last [_maxTraceCache] entries.
 final _error = JS('', 'Symbol("_error")');
 Map _primitiveErrorCache;
 const _maxErrorCache = 10;
 
 bool _isJsError(exception) {
   return JS('bool', '#.Error != null && # instanceof #.Error', global_,
@@ skipping 306 matching lines @@
 /// Libraries are not actually deferred in DDC, so this just returns a future
 /// that completes immediately.
 Future loadLibrary() => new Future.value();
 
 /// Defines lazy statics.
 void defineLazy(to, from) {
   for (var name in getOwnNamesAndSymbols(from)) {
     defineLazyProperty(to, name, getOwnPropertyDescriptor(from, name));
   }
 }