Support a ring of related breakpoints.
* breakpoint.c (watchpoint_del_at_next_stop): New, move here code from
other functions, add gdb_assert.
(update_watchpoint, watchpoint_check): Add gdb_assert. Use
watchpoint_del_at_next_stop.
(bpstat_check_watchpoint): Use watchpoint_del_at_next_stop.
(bpstat_stop_status): Handle ring in related_breakpoint.
(set_raw_breakpoint_without_location): Initialize ring in
related_breakpoint.
(delete_breakpoint): Handle ring in related_breakpoint, use
watchpoint_del_at_next_stop.
(map_breakpoint_numbers): Handle ring in related_breakpoint.
gdb/testsuite/
Support a ring of related breakpoints.
* gdb.base/watchpoint-delete.c: New file.
* gdb.base/watchpoint-delete.exp: New file.