More FFI fallout cleanup.

src/gevent/_ffi/watcher.py

@@ -106,6 +106,10 @@ class AbstractWatcherType(type):
     def _fill_watcher(cls, name, bases, cls_dict):
         # TODO: refactor smaller
         # pylint:disable=too-many-locals
+        if name.endswith('_'):
+            # Strip trailing _ added to avoid keyword duplications
+            # e.g., async_
+            name = name[:-1]
         def _mro_get(attr, bases, error=True):
             for b in bases:
                 try:

src/gevent/libuv/watcher.py

@@ -444,7 +444,7 @@ class _SimulatedWithAsyncMixin(object):
     _watcher_skip_ffi = True
 
     def __init__(self, loop, *args, **kwargs):
-        self._async = loop.async()
+        self._async = loop.async_()
         super(_SimulatedWithAsyncMixin, self).__init__(loop, *args, **kwargs)
 
     def _watcher_create(self, _args):
@@ -538,8 +538,6 @@ class child(_SimulatedWithAsyncMixin,
 
 class async_(_base.AsyncMixin, watcher):
 
-    _watcher_struct_name = 'uv_async_t'
-
     def _watcher_ffi_init(self, args):
         # It's dangerous to have a raw, non-initted struct
         # around; it will crash in uv_close() when we get GC'd,