ref: 8adc5a0fce7e50f8bf8e69e51274092a1a581cd6
dir: /sys/src/ape/lib/ap/gen/strrchr.c/
#include <string.h>
char*
strrchr(const char *s, int c)
{
	char *r;
	if(c == 0)
		return strchr(s, 0);
	r = 0;
	while(s = strchr(s, c))
		r = (char*)s++;
	return r;
}