* linux-low.c (linux_wait, linux_resume): Do not handle async I/O.

	* linux-low.c (linux_wait, linux_resume): Do not handle async I/O.
	* remote-utils.c (remote_open): Do not call disable_async_io.
	(block_async_io): Delete.
	(unblock_async_io): Make static.
	(initialize_async_io): New.
	* server.c (handle_v_cont): Handle async I/O here.
	(myresume): Likewise.  Move other common resume tasks here...
	(main): ... from here.  Call initialize_async_io.  Disable async
	I/O before the main loop.
	* server.h (initialize_async_io): Declare.
	(block_async_io, unblock_async_io): Delete prototypes.
	* spu-low.c (spu_resume, spu_wait): Do not handle async I/O here.