Plumb enum remove_bp_reason all the way to target_remove_breakpoint

Plumb enum remove_bp_reason all the way to target_remove_breakpoint

So the target knows whether we're detaching breakpoints.
Nothing uses the parameter in this patch yet.

gdb/ChangeLog:
2016-08-10  Pedro Alves  <palves@redhat.com>

	PR gdb/19187
	* break-catch-sig.c (signal_catchpoint_remove_location): Adjust
	interface.
	* break-catch-syscall.c (remove_catch_syscall):
	* breakpoint.c (enum remove_bp_reason): Moved to breakpoint.h.
	(remove_breakpoint_1): Pass 'reason' down.
	(remove_catch_fork, remove_catch_vfork, remove_catch_solib)
	(remove_catch_exec, remove_watchpoint, remove_masked_watchpoint)
	(base_breakpoint_remove_location, bkpt_remove_location)
	(bkpt_probe_remove_location, bkpt_probe_remove_location): Adjust
	interface.
	* breakpoint.h (enum remove_bp_reason): Moved here from
	breakpoint.c.
	(struct breakpoint_ops) <remove_location>: Add 'reason' parameter.
	* corelow.c (core_remove_breakpoint): New function.
	(init_core_ops): Install it as to_remove_breakpoint method.
	* exec.c (exec_remove_breakpoint): New function.
	(init_exec_ops): Install it as to_remove_breakpoint method.
	* mem-break.c (memory_remove_breakpoint): Adjust interface.
	* record-btrace.c (record_btrace_remove_breakpoint): Adjust
	interface.
	* record-full.c (record_full_remove_breakpoint)
	(record_full_core_remove_breakpoint): Adjust interface.
	* remote.c (remote_remove_breakpoint): Adjust interface.
	* target-debug.h (target_debug_print_enum_remove_bp_reason): New
	macro.
	* target-delegates.c: Regenerate.
	* target.c (target_remove_breakpoint): Add 'reason' parameter.
	* target.h (struct target_ops) <to_remove_breakpoint>: Add
	'reason' parameter.
	(target_remove_breakpoint, memory_remove_breakpoint): Add 'reason'
	parameter.