ChangeLog:
	* remote.c (remote_write_qxfer): New function.
	(remote_xfer_partial): Add handling for TARGET_OBJECT_SPU.
	(remote_read_qxfer): Do not cache empty objects.
	(_initialize_remote): Add PACKET_qXfer_spu_read and
	PACKET_qXfer_spu_write.
doc/ChangeLog:
	* gdb.texinfo (General Query Packets): Document qXfer:spu:read
	and qXfer:spu:write packets and mention them under qSupported.
gdbserver/ChangeLog:
	* remote-utils.c (decode_xfer_write): New function.
	* server.h (decode_xfer_write): Add prototype.
	* server.c (handle_query): Add PACKET_LEN argument.  Support
	qXfer:spu:read and qXfer:spu:write packets.
	(main): Pass packet_len to handle_query.
	* spu-low.c (spu_target_ops): Add spu_proc_xfer_spu.
	* target.h (target_ops): Add qxfer_spu.