Split various parser flavors to separate crates
Summary:
I think the easiest way to read this diff is to look at changes to `hphp/hack/src/parser/TARGETS`. The rest is just moving things around so that things will compile:
- various `ToOcaml` implementations are moved to the new crates now containing what they implement the trait for
- `make_syntax_tree` is moves from parser to syntax_tree, to avoid all the other parsers depending on minimal parser
- `rust_parser_ffi` is split off from `rust_to_ocaml`
- since so many things already change, I use this opportunity to change the style of imports to not repeat the path parts
Reviewed By: shiqicao
Differential Revision:
D17404555
fbshipit-source-id:
a83c8d0ec64cc44f1c7562684fd5c577eceab54b