[ovs-dev] [eviction 01/12] util: Move bitwise_copy() here, add new bitwise functions.

[Ethan Jackson]

>  * If you consider all of 'src' to be a single unsigned integer in network byte
>  * order, then bit N is the bit with value 2**N.  That is, bit 0 is the bit
>  * with value 1 in src[src_len - 1], bit 1 is the bit with value 2, bit 2 is
>  * the bit with value 4, ..., bit 8 is the bit with value 1 in src[src_len -
>  * 2], and so on.  Similarly for 'dst'.

This sounds clear to me.

> I don't want to do so in this case because it could greatly increase
> the cost of the function in cases where it is very cheap.

This feels like premature optimization to me, especially given how
complex the function is.  I don't feel particularly strongly about it
though so we can leave it.

Ethan