* breakpoint.c: Move defaults of watchpoint related macros into

	* breakpoint.c:  Move defaults of watchpoint related macros into
	target.h.
	* target.h:  Macros from breakpoint.c.  Conditionalize based on
	TARGET_HAS_HARDWARE_WATCHPOINTS.
	* i386v-nat.c procfs.c:  Use TARGET_HAS_HARDWARE_WATCHPOINTS
	instead of TARGET_CAN_USE_HARDWARE_WATCHPOINT to enable watchpoint
	code.
	* config/i386/nm-linux.h, config/mips/nm-irix4.h,
	config/pa/nm-hppab.h, config/sparc/tm-sparclite.h:  #define
	TARGET_HAS_HARDWARE_WATCHPOINTS to enable watchpoint code.