Recursive functions that may not be stack safe

[mlms13]

This is an incomplete list of functions that could blow the stack. At some point we should do a more thorough audit, but I thought for now I'd at least keep track as I come across things.

• Tree.flatten (see Rewrite Flatten to be stack safe #246)
• Tree.fill
• Tree.map
• Tree.apply
• Tree.bind
• Tree.zipWith
• Int.rangeAsList and Int.rangeAsArray
• List.flatten
• List.init
• List.chunk
• Array.takeWhile
• Array.chunk
• SequenceZipper.findLeftBy
• SequenceZipper.findRightBy

[mlms13]

This one is outside of the scope of Relude itself (as it's defined in Bastet, or possibly even in the OCaml standard library... not sure), but List.fold_right doesn't appear to be stack-safe (which I think is pretty normal for a foldr implementation), but it's used as the foundation for things like traverse and sequence which maybe makes those functions also not stack safe.

IIRC, PureScript ended up changing to a tail-recursive implementation of foldr, so we could start by digging in there.