nextafterf
float nextafterf(float, float);
debug("%a\n", nextafterf(tanhf(nums[i]), INFINITY));
testall(42.0, nextafterf(42.0, -INFINITY));
testall(nextafterf(42.0, INFINITY), 42.0);
testall(42.0, nextafterf(42.0, -INFINITY));
testall(nextafterf(42.0, INFINITY), 42.0);
stest(nextafterf, 0x1p-149f, f);
testf(idf(nextafterf(FLT_MAX, INFINITY)), INFINITY, ex_over);
testf(idf(nextafterf(INFINITY, 0.0)), FLT_MAX, 0);