second arg of call-with-values not in tail context

[Matthias Koeppe]

R5RS requires that the second argument passed to `call-with-values',
must be called via a tail call; see (r5rs)Proper tail recursion.

Guile calls the second argument via an ordinary call; this causes
stack overflows in many situations. Here is an example; this
construction frequently occurs when one uses the `receive' special
form.

(let loop ((i 1000))
  (if (> i 0)
      (call-with-values
          (lambda () (values 1))
        (lambda (x) (loop (- i 1))))))

Can we get this fixed?

-- 
Matthias Köppe -- http://www.math.uni-magdeburg.de/~mkoeppe