* linux-low.c (linux_wait_for_event): Update messages. Do not
reinsert auto-delete breakpoints.
* mem-break.c (struct breakpoint): Change return type of handler to
int.
(set_breakpoint_at): Update handler type.
(reinsert_breakpoint_handler): Return 1 instead of calling
delete_breakpoint.
(reinsert_breakpoint_by_bp): Check for the original breakpoint before
setting a new one.
(check_breakpoints): Delete auto-delete breakpoints and return 2.
* mem-break.h (set_breakpoint_at): Update handler type.
* thread-db.c (thread_db_create_event, thread_db_create_event): Update.
* win32-low.c (auto_delete_breakpoint): New.
(get_child_debug_event): Use it.