Silence ARI for valid calls to abort
    
    There are a handful of spots in gdb that validly call abort.  This
    patch adds the appropriate ARI marker to these lines, to silence the
    ARI report.  This also removes the "fix" call for "abort" from
    gdb_ari.sh; it was incorrect and now is not needed.
    
    gdb/ChangeLog
    2019-12-13  Tom Tromey  <tromey@adacore.com>
    
    	* contrib/ari/gdb_ari.sh: Remove "fix" call for abort.
    	* utils.c (abort_with_message, dump_core, internal_vproblem): Add
    	ARI marker to abort.
    	* event-top.c (handle_sigsegv): Add ARI marker to abort.
    
    Change-Id: I09ce6aa5010bbe4e5bb73ffdb727481be39d34d6