guile on ia64

[stefan]

Dear list,

  I would like to approve the patches I can supply for a stable
guile-1.5.3 with RB's patches from the alpha port.

  The garbage collection thingie and some code for the continuations I
could fix on the ia64-linux. With these patches I was able to run "make
check" without errors except the bit-thingies left from the alpha patch.
The changes need a review since it is partly new code and *very* target
specific. I use setcontext() and getcontext() to save the "other" stack.
This is the backing store on the Itanium. Please let me know if you want
it still in the 1.5 branch...

  I got yet another "important" request: The recent change in chars.h
(intptr_t -> scm_t_bits) should also go into the stable release.

Cheers,
        address@hidden