Use elfcore_write_linux_prstatus in gdb

[Pedro Alves]

On 01/21/2016 09:28 AM, Alan Modra wrote:
> The gdb side.  Nothing fancy here, and no support for targets that
> need gdbarch_elfcore_write_linux_prstatus, mips n32, sparc64 if
> writing any of pr_{u,s,cu,cs}time, and probably x86-64 x32.

Thanks a lot for doing all this!  I don't have spare cycles either to
drive this all the way to completion for all archs, I think we can still
move forward with it, by adding a stop-gap implementation those
archs, which just calls elfcore_write_prstatus.  I'll send it along
in a bit.

Thanks,
Pedro Alves