/* find a "name" for the RK value 'c'  */
static void kname(Proto *p, int pc, int c, const char **name)
/* find a "name" for the RK value 'c'  */
static void kname(Proto *p, int pc, int c, const char **name)
{
    TValue *kvalue = &p->k[INDEXK(c)];
    if (ttisstring(kvalue)) {
      *name = svalue(kvalue);
      return;
    }
  }
  else {
    const char *what = getobjname(p, pc, c, name);
    if (what && *what == 'c') {
      return;
    }
  }
  *name = "?";
}