A subsequent patch is going to move event-loop.c to gdbsupport. In a
review of an earlier version of this series, Pedro pointed out that
the resulting code would be cleaner if start_event_loop were not
shared -- because gdb and gdbserver have some different needs here --
and so this moves start_event_loop to main.c. Because the only caller
is there, it is also now static.
gdb/ChangeLog
2020-04-13 Tom Tromey <tom@tromey.com>