`ishift'
--------

ishift(I,COUNT)
     :: bit shift

RETURN
     integer

I COUNT
     integer

   * The absolute value of I is regarded as a bit string.

   * The sign of I is ignored and a non-negative integer is returned.

   * If COUNT is positive, then I is shifted to the right.  If COUNT is
     negative, then I is shifted to the left.

     [0] ctrl("hex",1);
     0x1
     [1] ishift(0x1000000,12);
     0x1000
     [2] ishift(0x1000,-12);
     0x1000000
     [3] ixor(0x1248,ishift(1,-16)-1);

References
     *Note `iand ior ixor': iand ior ixor.

