Improve end check on rs6000 prologue analyzer

[Eli Zaretskii]

> Date: Tue, 13 Mar 2007 00:05:10 +0100 (CET)
> From: Mark Kettenis <mark.kettenis@xs4all.nl>
> CC: gdb-patches@sourceware.org
> 
> > Yeesh!  I didn't know that.  Is there somewhere we could write it down
> > for test writers who make this same mistake, maybe?  I would have
> > merrily written tests that expected the tab :-(
> 
> Hmm, I'm not sure we have any documentation on this.  Eli, do you know
> a good location to put this info.

There's a section in gdbint.texinfo about the test suite, which seems
a suitable place.