Remove args from target detach

I was looking into adding a parameter to target_detach, and was
wondering what the args parameter was.  It seems like in the distant
past, it was possible to specify a signal number when detaching.  That
signal was injected in the process before it was detached.  There is an
example of code handling this in linux_nat_detach.  With today's GDB, I
can't get this to work.  Doing "detach 15" (15 == SIGTERM) doesn't work,
because detach is a prefix command and doesn't recognize the sub-command
15.  Doing "detach inferiors 15" doesn't work because it expects a list
of inferior id to detach.  Therefore, I don't think there's a way of
invoking detach_command with a non-NULL args.  I also didn't find any
documentation related to this feature.

I assume that this feature stopped working when detach was made a prefix
command, which is in f73adfeb8b (sorry,
there's no commit title) from 2006.  Given that this feature was broken
for such a long time and we haven't heard anything (AFAIK, I did not
find any related bug), I think it's safe to remove it, as well as the
args parameter to target_detach.  If someone wants to re-introduce it, I
would suggest rethinking the user interface, and in particular would
suggest using signal name instead of numbers.

I tried to fix all the impacted code, but I might have forgotten some
spots.  It shouldn't be hard to fix if that's the case.  I also couldn't
build-test everything I changed, especially the nto and solaris stuff.

gdb/ChangeLog:

	* target.h (struct target_ops) <to_detach>: Remove args
	parameter.
	(target_detach): Likewise.
	* target.c (dispose_inferior): Adjust.
	(target_detach): Remove args parameter, adjust.
	* aix-thread.c (aix_thread_detach): Adjust.
	* corefile.c (core_file_command): Adjust.
	* corelow.c (core_detach): Adjust.
	* darwin-nat.c (darwin_detach): Adjust.
	* gnu-nat.c (gnu_detach): Adjust.
	* inf-ptrace.c (inf_ptrace_detach): Adjust.
	* infcmd.c (detach_command): Adjust
	* infrun.c (follow_fork_inferior): Adjust.
	(handle_vfork_child_exec_or_exit): Adjust.
	* linux-fork.c (linux_fork_detach): Remove args parameter.
	* linux-fork.h (linux_fork_detach): Likewise.
	* linux-nat.c (linux_nat_detach): Likewise, and adjust.
	* linux-thread-db.c (thread_db_detach): Likewise.
	* nto-procfs.c (procfs_detach): Likewise.
	* procfs.c (procfs_detach): Likewise.
	(do_detach): Remove signo parameter.
	* record.c (record_detach): Remove args parameter.
	* record.h (record_detach): Likewise.
	* remote-sim.c (gdbsim_detach): Likewise.
	* remote.c (remote_detach_1): Likewise.
	(remote_detach): Likewise.
	(extended_remote_detach): Likewise.
	* sol-thread.c (sol_thread_detach): Likewise.
	* target-delegates.c: Re-generate.
	* top.c (struct qt_args) <args>: Remove field.
	(kill_or_detach): Don't pass args.
	(quit_force): Don't set args.
	* windows-nat.c (windows_detach): Remove args parameter.

gdb/linux-thread-db.c

@@ -1090,13 +1090,13 @@ record_thread (struct thread_db_info *info,
 }
 
 static void
-thread_db_detach (struct target_ops *ops, const char *args, int from_tty)
+thread_db_detach (struct target_ops *ops, int from_tty)
 {
   struct target_ops *target_beneath = find_target_beneath (ops);
 
   delete_thread_db_info (ptid_get_pid (inferior_ptid));
 
-  target_beneath->to_detach (target_beneath, args, from_tty);
+  target_beneath->to_detach (target_beneath, from_tty);
 
   /* NOTE: From this point on, inferior_ptid is null_ptid.  */