Move _fatal from dart:core to dart:_internal

runtime/lib/async_patch.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 "dart:_internal";
 
 // We need to pass the value as first argument and leave the second and third
 // arguments empty (used for error handling).
 // See vm/ast_transformer.cc for usage.
 Function _asyncThenWrapperHelper(continuation) {
@@ skipping 79 matching lines @@
   // execution of the generator.
   //
   // TODO(hausner): Per spec, the generator should be suspended before
   // exiting when the stream is closed. We could add a getter like this:
   // get isCancelled => controller.hasListener;
   // The generator would translate a 'yield e' statement to
   // controller.add(e);
   // suspend;
   // if (controller.isCancelled) return;
   bool add(event) {
-    if (!onListenReceived) _fatal("yield before stream is listened to!");
-    if (isSuspendedAtYield) _fatal("unexpected yield");
+    if (!onListenReceived) fatal("yield before stream is listened to!");
+    if (isSuspendedAtYield) fatal("unexpected yield");
     // If stream is cancelled, tell caller to exit the async generator.
     if (!controller.hasListener) {
       return true;
     }
     controller.add(event);
     scheduleGenerator();
     isSuspendedAtYield = true;
     return false;
   }
 
   // Adds the elements of stream into this controller's stream.
   // The generator will be scheduled again when all of the
   // elements of the added stream have been consumed.
   // Returns true if the caller should terminate
   // execution of the generator.
   bool addStream(Stream stream) {
-    if (!onListenReceived) _fatal("yield before stream is listened to!");
+    if (!onListenReceived) fatal("yield before stream is listened to!");
     // If stream is cancelled, tell caller to exit the async generator.
     if (!controller.hasListener) return true;
     isAdding = true;
     var whenDoneAdding =
         controller.addStream(stream as Stream, cancelOnError: false);
     whenDoneAdding.then((_) {
       isAdding = false;
       scheduleGenerator();
       if (!isScheduled) isSuspendedAtYield = true;
     });
@@ skipping 54 matching lines @@
       // suspended at an await.
       if (isSuspendedAtYield) {
         scheduleGenerator();
       }
     }
     return cancellationCompleter.future;
   }
 }
 
 @patch void _rethrow(Object error, StackTrace stackTrace) native "Async_rethrow";