Create nat/i386-dregs.h

Create nat/i386-dregs.h

This commit moves code to be shared from i386-{nat,low}.[ch]
into a new file, nat/i386-dregs.h.

gdb/
2014-06-18  Gary Benson  <gbenson@redhat.com>

	* nat/i386-dregs.h: New file.
	* Makefile.in (HFILES_NO_SRCDIR): Add the above.
	* i386-nat.h (i386-dregs.h): New include.
	(DR_FIRSTADDR): Now in i386-dregs.h.
	(DR_LASTADDR): Likewise.
	(DR_NADDR): Likewise.
	(DR_STATUS): Likewise.
	(DR_CONTROL): Likewise.
	(i386_debug_reg_state): Likewise.
	* i386-nat.c (ALL_DEBUG_REGISTERS): Likewise.

gdb/gdbserver/
2014-06-18  Gary Benson  <gbenson@redhat.com>

	* i386-low.h (i386-dregs.h): New include.
	(DR_FIRSTADDR): Now in i386-dregs.h.
	(DR_LASTADDR): Likewise.
	(DR_NADDR): Likewise.
	(DR_STATUS): Likewise.
	(DR_CONTROL): Likewise.
	(i386_debug_reg_state): Likewise.
	(i386_dr_insert_watchpoint): Likewise.
	(i386_dr_remove_watchpoint): Likewise.
	(i386_dr_region_ok_for_watchpoint): Likewise.
	(i386_dr_stopped_data_address): Likewise.
	(i386_dr_stopped_by_watchpoint): Likewise.
	* i386-low.c (ALL_DEBUG_REGISTERS): Likewise.