S9fES  (bit-op integer1 integer2 integer3 ...)  ==>  integer

BIT-OP implements the bitwise operators summarized in the below
table. The operation itself is passed to BIT-OP as INTEGER1
(OP in the table) and the operands are passed as INTEGER2 (A)
and INTEGER3 (B), etc.

 Op | Result            | Common name
-------------------------------------
  0 |     0             | CLEAR
  1 |     A  and     B  | AND
  2 |     A  and not(B) |
  3 |     A             |
  4 | not(A) and     B  |
  5 |                B  |
  6 |     A  xor     B  | XOR
  7 |     A  or      B  | OR
  8 | not(A  or      B) | NOR
  9 | not(A  xor     B) | NXOR
 10 |            not(B) | NOT *
 11 |     A  or  not(B) |
 12 | not(A)            | NOT *
 13 | not(A) or      B  |
 14 | not(A  and     B) | NAND
 15 | not(0)            | SET
 16 |     A  shl     B  | shift left
 17 |     A  shr     B  | shift right

* NOT is a binary operation here, where the value of the other
operand does not matter.

When more than two operands are present, the operation will be
performed left-associatively on all operands, e.g.:

(bit-op 16 1 2 3 4)  ==>  512  ; ((1 shl 2) shl 3) shl 4

Note that BIT-OP operates only on an implementation-dependent subset
of integers. The maximum value of an operand A or B is equal to the
value of (bit-op 15 0 0). When passing a larger operand or a negative
operand to BIT-OP, it will signal an error. The same happens when OP
is outside of the range 0..17.

(bit-op  0 123 456)  ==>    0  ; clear
(bit-op  1   7  10)  ==>    2  ; and
(bit-op  7   7   8)  ==>   15  ; or
(bit-op 16   1   8)  ==>  256  ; shift left
