bitstring: add constant folding for bituquotient operator
bitstring: add constant folding for bituquotient operator

Implements the reduction of two constant inputs being reduced
to constant for the bituquotient operator.

Signed-off-by: Helge Bahmann <c5618920f622561f9c0ec5c42219c4c08180149f@chaoticmind.net>

phate/jive,phate/jive,phate/jive