* gdbarch.sh: Remove deprecated_register_byte.

	* gdbarch.sh: Remove deprecated_register_byte.
	* gdbarch.c, gdbarch.h: Regenerate.
	* arch-utils.h (generic_register_size, generic_register_byte): Remove.
	* arch-utils.c (generic_register_size, generic_register_byte): Remove.

	* regcache.h (regcache_valid_p): Make REGCACHE parameter const.
	* regcache.c (regcache_valid_p): Allow to query cooked registers in
	read-only register caches.  Make REGCACHE parameter const.
	(regcache_dump): Do not check DEPRECATED_REGISTER_BYTE.

	* mi/mi-main.c (old_regs): Remove.
	(mi_setup_architecture_data, _initialize_mi_main): Remove.
	(register_changed_p): Reimplement to compare two register caches.
	(mi_cmd_data_list_changed_registers): Update caller.
	* mi/mi-main.h (mi_setup_architecture_data): Remove.
	* mi/mi-interp.c (mi_interpreter_init): Do not call
	mi_setup_architecture_data.