ref: 5d1501e35338badd9a2958f1c1c68ad52ea2b020
dir: /lib/c/strcat.c/
#include <string.h>
#undef strcat
char *
strcat(char * restrict dst, const char * restrict src)
{
char *ret = dst;
while (*dst)
++dst;
while (*dst++ = *src++)
;
return ret;
}