backport eh fix to 4.0

[Alan Modra]

Hi Mark,
  I'd like to apply my fix for pr25176 to the 4.0 branch.  I didn't
apply it at the time because function.c:expand_function_end looks a
little different in 4.0 and I wanted to check that my patch was correct
there.  Then I forgot all about it..

A little investigation reveals that the expand_function_end difference
is due to 4.0 missing one of rth's patches,
http://gcc.gnu.org/ml/gcc-patches/2005-09/msg01078.html.  This bugfix
patch seems like a useful one to have on the branch so I bootstrapped
and regression tested it along with mine.  OK to apply?

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre