Shahab suggested we get rid of the verbosity level for the ARC debug
logging [1]. This patch does that, before doing any other change.
gdb/ChangeLog:
* arc-tdep.h (arc_debug): Change type to bool.
* arc-tdep.c (arc_debug): Change type to bool.
(arc_analyze_prologue): Adjust.
(_initialize_arc_tdep): Use add_setshow_boolean_cmd.
* arc-linux-nat.c (ps_get_thread_area): Adjust.