Guile implements this library in terms of SRFI-69, which is a bit vague on
the arity of hash functions, whereas `(rnrs hashtables)' explicitly
specifies unary ones.
* module/rnrs/hashtables.scm (wrap-hash-function): Assume SRFI-69 will pass
the table capacity as the second argument; return the result of proc
modulo the capacity.
* test-suite/tests/r6rs-hashtables.test (make-hashtable): New test case for
hash functions that return large values.