Create gdb/break-catch-syscall.c

Create gdb/break-catch-syscall.c

This commits cleans up the gdb/breakpoint.c file and moves everything
that is related to the 'catch syscall' command to the new file
gdb/break-catch-syscall.c.  This is just code movement, and the only
new part is the adjustment needed on 'catching_syscall_number' to use
the new 'breakpoint_find_if' function insted of relying on the
ALL_BREAKPOINTS macro.

Tested by running the 'gdb.base/catch-syscall.exp' testcase.

gdb/ChangeLog:
2015-03-11  Sergio Durigan Junior  <sergiodj@redhat.com>

	* Makefile.in (SFILES): New source break-catch-syscall.c.
	(COMMON_OBS): New object break-catch-syscall.o.
	* break-catch-syscall.c: New file.
	* breakpoint.c: Remove inclusion of "xml-syscall.h".
	(syscall_catchpoint_p): Move declaration to break-catch-syscall.c
	(struct syscall_catchpoint): Likewise.
	(dtor_catch_syscall): Likewise.
	(catch_syscall_inferior_data): Likewise.
	(struct catch_syscall_inferior_data): Likewise.
	(get_catch_syscall_inferior_data): Likewise.
	(catch_syscall_inferior_data_cleanup): Likewise.
	(insert_catch_syscall): Likewise.
	(remove_catch_syscall): Likewise.
	(breakpoint_hit_catch_syscall): Likewise.
	(print_it_catch_syscall): Likewise.
	(print_one_catch_syscall): Likewise.
	(print_mention_catch_syscall): Likewise.
	(print_recreate_catch_syscall): Likewise.
	(catch_syscall_breakpoint_ops): Likewise.
	(syscall_catchpoint_p): Likewise.
	(create_syscall_event_catchpoint): Likewise.
	(catch_syscall_split_args): Likewise.
	(catch_syscall_command_1): Likewise.
	(is_syscall_catchpoint_enabled): Likewise.
	(catch_syscall_enabled): Likewise.
	(catching_syscall_number): Likewise.
	(catch_syscall_completer): Likewise.
	(clear_syscall_counts): Likewise.
	(initialize_breakpoint_ops): Move initialization of syscall
	catchpoints to break-catch-syscall.c.
	(_initialize_breakpoint): Move code related to syscall catchpoints
	to break-catch-syscall.c.