non-OS dependent setjmp for i386

[Joel Sherrill]

Did my original patch include this?  It did not make it into newlib 1.8.0.

If you look at the setjmp implementations in newlib 1.8.0, the ones for
the i386 are for go32 and sysvi386 -- neither is strictly speaking target
OS independent.  I thought I submitted one (or think I did) which was not
OS dependent.  Does someone who can put it in still have it or do I need
to remerge it against 1.8.0 and submit the patch again?

Was there something wrong with this patch or did it just slip through the
cracks?

--joel