Feature request: Add bitwise operators on integer64

[dvg-p4]

Bitwise AND/OR and left/right shifts would be very useful when working with integers that are encoding multiple sub-values based on bit position.

[dvg-p4]

Workaround: use combinations of %% 2^n, %/% 2^n, * 2^n to extract and manipulate contiguous bits.

E.g. to emulate bitwise AND with 0b111110000 and extract bits 9 to 5:

> input
integer64
[1] 123456789 987654321
> as.bitstring(input)
[1] "0000000000000000000000000000000000000111010110111100110100010101" "0000000000000000000000000000000000111010110111100110100010110001"
> as.bitstring(input %% 2^9 %/% 2^4 * 2^4)
[1] "0000000000000000000000000000000000000000000000000000000100010000" "0000000000000000000000000000000000000000000000000000000010110000"