PASS: bignum-init
PASS: bignum-init-rand
PASS: bignum-copyswap
PASS: bignum-lengths
PASS: bignum-add
PASS: bignum-mul
PASS: bignum-pow
PASS: bignum-sub
PASS: bignum-shift
PASS: bignum-cmp
PASS: bignum-bits
PASS: bignum-div
PASS: bignum-invert
PASS: bignum-prime