[RFA/powerpc] Add handling for stack-check sequences in prologue

[Jerome Guitton]

Joel Brobecker (brobecker@adacore.com):

> > 2008-09-01  Jerome Guitton  <guitton@adacore.com>
> > 
> > 	* rs6000-tdep.c (rs6000_fetch_instruction)
> > 	(rs6000_skip_stack_check): New functions.
> > 	(skip_prologue): Skip stack check sequence.
> 
> I just reviewed the patch, and it looks OK to me. I think there are
> other maintainers who are also interested in powerpc, so give it a
> few more days (say until Fri) to see if they might want to comment
> and then commit if no objection.

Time's up :)
Now committed.
Thanks,
Jerome