[rfc] Print solib events in mi-mode

[Kris Warkentin]

> That's not really the problem - the breakpoint is already there, it's
> the same breakpoint we stop at for stop-on-solib-events.  The real
> trick is going to be reporting the events - SOLIB_HAVE_LOAD_EVENT
> and SOLIB_LOADED_LIBRARY_PATHNAME.  The model has to change a little
> since more than one library can be reported at once in the svr4 model.

Well, SOLIB_LOADED_LIBRARY_PATHNAME is only used twice.  Once it just fills
a string (triggered_dll_pathname) which is only used for printing.
Therefore we could return a comma separated list or something pretty like
that.

The other is just to compare against a dll_pathname so we could get away
with creating a SOLIB_WAS_(UN)LOADED(pid, "libname") and have the backend
check through the list for libname.

Okay...that seems reasonable.  Another question: since we've already got a
solib breakpoint set in svr4, we don't need to call
create_solib_load_event_breakpoint() like somsolib.c and pa64solib.c do.
Can you have multiple types associated with a single break or do we just set
another at the same address?

cheers,

Kris