[GDBserver] Move Z packet defines and type convertion routines to shared code.

[GDBserver] Move Z packet defines and type convertion routines to shared code.

The Aarch64, MIPS and x86 Linux backends all have Z packet number
defines and corresponding protocol number to internal type convertion
routines.  Factor them all out to gdbserver's core code, so we only
have one shared copy.

Tested on x86_64 Fedora 20, and also cross built for aarch64-linux-gnu
and mips-linux-gnu.

gdb/gdbserver/
2014-05-20  Pedro Alves  <palves@redhat.com>

	* mem-break.h: Include break-common.h.
	(Z_PACKET_SW_BP, Z_PACKET_HW_BP, Z_PACKET_WRITE_WP)
	(Z_PACKET_READ_WP, Z_PACKET_ACCESS_WP): New defines.
	(Z_packet_to_target_hw_bp_type): New declaration.
	* mem-break.c (Z_packet_to_target_hw_bp_type): New function.
	* i386-low.c (Z_PACKET_HW_BP, Z_PACKET_WRITE_WP, Z_PACKET_READ_WP)
	(Z_PACKET_ACCESS_WP): Delete macros.
	(Z_packet_to_hw_type): Delete function.
	* i386-low.h: Don't include break-common.h here.
	(Z_packet_to_hw_type): Delete declaration.
	* linux-x86-low.c (x86_insert_point, x86_insert_point): Call
	Z_packet_to_target_hw_bp_type instead of Z_packet_to_hw_type.
	* win32-i386-low.c (i386_insert_point, i386_remove_point): Call
	Z_packet_to_target_hw_bp_type instead of Z_packet_to_hw_type.
	* linux-aarch64-low.c: Don't include break-common.h here.
	(Z_PACKET_SW_BP, Z_PACKET_HW_BP, Z_PACKET_WRITE_WP)
	(Z_PACKET_READ_WP, Z_PACKET_ACCESS_WP): Delete macros.
	(Z_packet_to_target_hw_bp_type): Delete function.
	* linux-mips-low.c (rsp_bp_type_to_target_hw_bp_type): Delete
	function.
	(mips_insert_point, mips_remove_point): Use
	Z_packet_to_target_hw_bp_type.