Unified support for hardware breakpoints and watchpoints on

	Unified support for hardware breakpoints and watchpoints on
	x86 targets:

	* config/i386/nm-i386.h: New file.

	* config/i386/nm-i386.h: (i386_cleanup_dregs)
	(i386_insert_watchpoint, i386_remove_watchpoint)
	(i386_region_ok_for_watchpoint, i386_stopped_by_hwbp)
	(i386_stopped_data_address, i386_insert_hw_breakpoint)
	(i386_remove_hw_breakpoint): Declare prototypes.
	[I386_USE_GENERIC_WATCHPOINTS] (TARGET_CAN_USE_HARDWARE_WATCHPOINT):
	Define if not already defined.
	(TARGET_REGION_OK_FOR_HW_WATCHPOINT, HAVE_CONTINUABLE_WATCHPOINT)
	(STOPPED_BY_WATCHPOINT, target_stopped_data_address)
	(target_insert_watchpoint, target_remove_watchpoint)
	(target_insert_hw_breakpoint, target_remove_hw_breakpoint): Define
	to call the appropriate i386_* functions.

	* i386-nat.c: New file.

	* i386-nat.c (I386_DR_CONTROL_MASK, I386_DR_LOCAL_ENABLE)
	(I386_DR_GLOBAL_ENABLE, I386_DR_DISABLE, I386_DR_SET_RW_LEN)
	(I386_DR_GET_RW_LEN, I386_DR_WATCH_HIT): New macros.
	(dr_mirror, dr_status_mirror, dr_control_mirror, dr_ref_count)
	(maint_show_dr): New variables.
	(i386_cleanup_dregs, i386_show_dr, i386_length_and_rw_bits)
	(i386_insert_aligned_watchpoint, i386_remove_aligned_watchpoint)
	(i386_handle_nonaligned_watchpoint, i386_insert_watchpoint)
	(i386_remove_watchpoint, i386_region_ok_for_watchpoint)
	(i386_stopped_data_address, i386_stopped_by_hwbp)
	(i386_insert_hw_breakpoint, i386_remove_hw_breakpoint): New
	functions.
	(_initialize_i386_nat): New function.
	[I386_USE_GENERIC_WATCHPOINTS]: Add new	maint command
	`show-debug-regs', sets maint_show_dr to non-zero value and
	activates debugging print-outs in functions which insert, remove,
	and test watchpoints and hardware breakpoints.

	* Makefile.in (i386-nat.o): New target.
	(ALLDEPFILES): Add i386-nat.o.