s/maint_show_dr/debug_hw_points/g in i386-nat.c
s/inf_state/state/g in i386-low.c
Add STATE parameter to i386-nat.c's i386_update_inferior_debug_regs
Abstract can-we-set-{control,addresses} checks,
and add macros for i386_dr_low_{get,set}_{addr,status,control}
New (empty) files nat/i386-dregs.[ch] (and buildsystem changes)