ref: f764b7c8342bd000d43eea624bc6265b8f3a8a7f
dir: /src/libc/string/strrchr.c/
#include <string.h>
#undef strrchr
char *
strrchr(const char *s, int c)
{
	const char *t = s;
	while (*t)
		++t;
	while (t > s && *t != c)
		--t;
	return (*t == c) ? t : NULL;
}