Rationalize coercions

test/dart_codegen/expect/async/schedule_microtask.dart

 part of dart.async;
  typedef void _AsyncCallback();
  class _AsyncCallbackEntry {final _AsyncCallback callback;
  _AsyncCallbackEntry next;
  _AsyncCallbackEntry(this.callback);
 }
  _AsyncCallbackEntry _nextCallback;
  _AsyncCallbackEntry _lastCallback;
  _AsyncCallbackEntry _lastPriorityCallback;
  bool _isInCallbackLoop = false;
@@ skipping 12 matching lines @@
   _asyncRunCallbackLoop();
   }
  finally {
   _lastPriorityCallback = null;
    _isInCallbackLoop = false;
    if (_nextCallback != null) _AsyncRun._scheduleImmediate(_asyncRunCallback);
   }
 }
  void _scheduleAsyncCallback(callback) {
 if (_nextCallback == null) {
-  _nextCallback = _lastCallback = new _AsyncCallbackEntry(DEVC$RT.cast(callback, dynamic, __t28, "CastGeneral", """line 66, column 61 of dart:async/schedule_microtask.dart: """, callback is __t28, false));
+  _nextCallback = _lastCallback = new _AsyncCallbackEntry(DEVC$RT.cast(callback, dynamic, __t28, "CompositeCast", """line 66, column 61 of dart:async/schedule_microtask.dart: """, callback is __t28, false));
    if (!_isInCallbackLoop) {
     _AsyncRun._scheduleImmediate(_asyncRunCallback);
     }
   }
  else {
-  _AsyncCallbackEntry newEntry = new _AsyncCallbackEntry(DEVC$RT.cast(callback, dynamic, __t28, "CastGeneral", """line 71, column 60 of dart:async/schedule_microtask.dart: """, callback is __t28, false));
+  _AsyncCallbackEntry newEntry = new _AsyncCallbackEntry(DEVC$RT.cast(callback, dynamic, __t28, "CompositeCast", """line 71, column 60 of dart:async/schedule_microtask.dart: """, callback is __t28, false));
    _lastCallback.next = newEntry;
    _lastCallback = newEntry;
   }
 }
  void _schedulePriorityAsyncCallback(callback) {
-_AsyncCallbackEntry entry = new _AsyncCallbackEntry(DEVC$RT.cast(callback, dynamic, __t28, "CastGeneral", """line 84, column 55 of dart:async/schedule_microtask.dart: """, callback is __t28, false));
+_AsyncCallbackEntry entry = new _AsyncCallbackEntry(DEVC$RT.cast(callback, dynamic, __t28, "CompositeCast", """line 84, column 55 of dart:async/schedule_microtask.dart: """, callback is __t28, false));
  if (_nextCallback == null) {
   _scheduleAsyncCallback(callback);
    _lastPriorityCallback = _lastCallback;
   }
  else if (_lastPriorityCallback == null) {
   entry.next = _nextCallback;
    _nextCallback = _lastPriorityCallback = entry;
   }
  else {
   entry.next = _lastPriorityCallback.next;
    _lastPriorityCallback.next = entry;
    _lastPriorityCallback = entry;
    if (entry.next == null) {
     _lastCallback = entry;
     }
   }
 }
  void scheduleMicrotask(void callback()) {
 if (identical(_ROOT_ZONE, Zone.current)) {
   _rootScheduleMicrotask(null, null, _ROOT_ZONE, callback);
    return;}
  Zone.current.scheduleMicrotask(Zone.current.bindCallback(callback, runGuarded: true));
 }
  class _AsyncRun {external static void _scheduleImmediate(void callback());
 }
  typedef void __t28();