Hello,

On AIX, we were no longer able to debug a simple program:

    (gdb) start
    Temporary breakpoint 1 at 0x10041548: file task_switch.adb, line 7.
    Starting program: /[...]/task_switch 
    zsh: 675900 illegal hardware instruction (core dumped)  /[...]/gdb task_switch

This is because we were using an global target_ops to store the target
underneath the AIX thread layer, and this global wasn't really as well
initiatialized as you'd think. That was a good opportunity for getting
rid of it.

As I was working on this, I wondered why the aix_thread_kill was
needed at all. The only think that this method does extra is preserving
the inferior ptid. I don't see why this is necessary. I did a little
bit of testing and found nothing wrong with removing it, so I removed it,
at least for now.

2009-03-15  Joel Brobecker  <brobecker@adacore.com>

        Modernize the aix-thread later by getting rid of the base_target
        global.  This brings back to life the AIX port which was otherwise
        crashing all the time.

        * aix-thread.c (base_target): Delete.
        (pd_enable): Do not set base_target.
        (aix_thread_attach): Use find_target_beneath instead of base_target.
        (aix_thread_detach, aix_thread_resume, aix_thread_wait)
        (aix_thread_fetch_registers, aix_thread_store_registers),
        (aix_thread_xfer_partial, aix_thread_mourn_inferior)
        (aix_thread_thread_alive, aix_thread_pid_to_str): Likewise.
        (aix_thread_kill): Delete. Does not seem necessary.
        (init_aix_thread_ops): Do not set aix_thread_ops.to_kill.

Tested on powerpc-aix. Checked in.

The only regression left that I'm seeing, now, is with core files.
Looking into it...

-- 
Joel