throw.c SCM_CDAR line 739

[Bill Schottstaedt]

If SCM_DEBUG_PAIR_ACCESSES is 1, throw.c line 739 triggers an error
about accessing a non-pair.  Perhaps it should be:

   !scm_is_pair (SCM_CAR (wind_goal)) || !scm_is_eq (SCM_CDAR (wind_goal), 
jmpbuf);

The wind list list in question normally looks like:

(#<winder 2ab3a6553020> #<frame 2ab3a659deb0> #<winder 2ab3a655a760> #<winder 
2ab3a655a9c0> #<frame 2ab3a65a2a90> (#t . #<jmpbuffer (active) 7ffffff00bf0>))

as mentioned in dynwind.c -- SCM_CDAR(#<winder>) is causing the error in this 
case.


(This tripped me earlier while chasing the 64-bit gcc 4 problem).