ref: f5960a5c076adc9b608e51a537014e99de2adf54
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;
}