asyncio: sync with Tulip

* Fix a race condition in BaseSubprocessTransport._try_finish().

  If the process exited before the _post_init() method was called, scheduling
  the call to _call_connection_lost() with call_soon() is wrong:
  connection_made() must be called before connection_lost().

  Reuse the BaseSubprocessTransport._call() method to schedule the call to
  _call_connection_lost() to ensure that connection_made() and
  connection_lost() are called in the correct order.

* Add repr(PipeHandle)

* Fix typo

Lib/asyncio/base_subprocess.py

@@ -153,7 +153,7 @@ def _try_finish(self):
         if all(p is not None and p.disconnected
                for p in self._pipes.values()):
             self._finished = True
-            self._loop.call_soon(self._call_connection_lost, None)
+            self._call(self._call_connection_lost, None)
 
     def _call_connection_lost(self, exc):
         try:

Lib/asyncio/windows_events.py

@@ -402,7 +402,7 @@ def finish_accept_pipe(trans, key, ov):
             ov.getresult()
             return pipe
 
-        # FIXME: Tulip issue 196: why to we neeed register=False?
+        # FIXME: Tulip issue 196: why do we need register=False?
         # See also the comment in the _register() method
         return self._register(ov, pipe, finish_accept_pipe,
                               register=False)

Lib/asyncio/windows_utils.py

@@ -134,6 +134,13 @@ class PipeHandle:
     def __init__(self, handle):
         self._handle = handle
 
+    def __repr__(self):
+        if self._handle != -1:
+            handle = 'handle=%r' % self._handle
+        else:
+            handle = 'closed'
+        return '<%s %s>' % (self.__class__.__name__, handle)
+
     @property
     def handle(self):
         return self._handle