* monitor.c (monitor_supply_register): Add REGCACHE parameter, use

	* monitor.c (monitor_supply_register): Add REGCACHE parameter, use
	it instead of current_regcache.
	(parse_register_dump): Add REGCACHE parameter, pass it to
	supply_register callback.
	(monitor_dump_reg_block): Add REGCACHE parameter, pass it to
	parse_register_dump.
	(monitor_dump_regs): Add REGCACHE parameter, pass it to
	parse_register_dump and dumpregs callback.
	(monitor_wait): Pass current_regcache to parse_register_dump and
	monitor_dump_regs.
	(monitor_fetch_register): Pass current_regcache to
	monitor_supply_register.
	(monitor_fetch_registers): Pass current_regcache to
	monitor_dump_regs.
	* monitor.h (struct monitor_ops): Add REGCACHE parameter to
	supply_register and dumpregs callbacks.
	(monitor_supply_register, monitor_dump_reg_block): Update
	prototypes.
	* dbug-rom.c (dbug_supply_register): Add REGCACHE parameter.  Pass
	it to monitor_supply_register.
	* dink32-rom.c (dink32_supply_register): Likewise.
	* ppcbug-rom.c (ppcbug_supply_register): Likewise.
	* m32r-rom.c (m32r_supply_register): Likewise.  Also, use REGCACHE
	instead of current_regcache.