win,pipe: ipc code does not support async read

The implementation of IPC pipe in libuv on Windows does not properly support
async reading. This means we cannot set the more parameter without likely
causing hangs. Sorry this is yet another followup to libuv#4511.

Fixes libuv#4548

src/win/pipe.c

@@ -2094,17 +2094,13 @@ static int uv__pipe_read_ipc(uv_loop_t* loop, uv_pipe_t* handle) {
       /* Store the pending socket info. */
       uv__pipe_queue_ipc_xfer_info(handle, xfer_type, &xfer_info);
     }
-
-    more = 1;
   }
 
   /* Return whether the caller should immediately try another read call to get
-   * more data. */
-  if (more && *data_remaining == 0) {
-    /* TODO: use PeekNamedPipe to see if it is really worth trying to do
-     * another ReadFile call. */
-  }
-
+   * more data. Calling uv__pipe_read_exactly will hang if there isn't data
+   * available, so we cannot do this unless we are guaranteed not to reach that.
+   */
+  more = *data_remaining > 0;
   return more;
 
 invalid: