code: func isSmallInt(op *opcode) bool {
  	if op.value == OP_0 || (op.value >= OP_1 && op.value <= OP_16) {
  		return true
  	}
  	return false
  }
docs: // isSmallInt returns whether or not the opcode is considered a small integer,
  // which is an OP_0, or OP_1 through OP_16.