* inferior.h (read_pc_pid, write_pc_pid): Remove.

	* inferior.h (read_pc_pid, write_pc_pid): Remove.
	* regcache.h (regcache_read_pc, regcache_write_pc): Add prototypes.

	* regcache.c (read_pc_pid): Remove, replace by ...
	(regcache_read_pc): ... this function.
	(write_pc_pid): Remove, replace by ...
	(regcache_write_pc): ... this function.
	(read_pc, write_pc): Update.

	* infrun.c (displaced_step_prepare): Replace read_pc_pid and
	write_pc_pid by regcache_read_pc and regcache_write_pc.
	(displaced_step_fixup): Likewise.
	(resume): Likewise.  Use regcache arch instead of current_gdbarch.
	(prepare_to_proceed): Likewise.
	(proceed): Likewise.
	(adjust_pc_after_break): Likewise.
	(handle_inferior_event): Likewise.

	* linux-nat.c (cancel_breakpoint): Likewise.
	* linux-thread-db.c (check_event): Likewise.
	* aix-thread.c (aix_thread_wait): Likewise.
	* tracepoint.c (trace_dump_command): Likewise.