ref: 3223acae34b67330351ac8071c35ff9f77ee5b83
dir: /sys/src/ape/lib/ap/gen/div.c/
#include <stdlib.h>
div_t div(int numer, int denom)
{
div_t ans;
ans.quot=numer/denom; /* assumes division truncates */
ans.rem=numer-ans.quot*denom;
return ans;
}