Currently a bit limited, unfortunately printf's `%a` specifier is
absolutely unreadable.
So we add `hex` and `octal` with `0x` and `0` prefixes respectively,
and also take a number but currently only allow 16 and 8.
The output is truncated to integer, so scale values other than 0 are
invalid and 0 is implied.
The docs mention this may change.
Just as `math "bitand(5,3)"` and `math "bitor(6,2)"`.
These cast to long long before doing their thing,
so they truncate to an integer, producing weird results with floats.
That's to be expected because float representation is *very*
different, and performing bitwise operations on floats feels quite useless.
Fixes#7281.
Was: "parameter expansion takes before expressions are evaluated."
Now: "parameter expansion happens before expressions are evaluated."
I suspect the original intent was to use "takes place," but I see "happens" as less idiomatic and therefore may benefit non-English-native users.
