Summary:
Just a bunch of minor changes.
- The mutable field doesn't need to be mutable: it's only mutated once in the code somewhere that doesn't even need to mutate
- Hence the type can be public
- All the `ms_get_*` functions are replaced by field accesses
- `CMethod_signature` -> `CMethodSignature` while I'm at it, although maybe that's bad since other files in clang/ follow the former convention
- `type method_signature` -> `type t`
- `pp` function instead of `to_string`, since it's used with `fprintf`. This gets rid of the only caller of `IList.to_string`.
Reviewed By: dulmarod
Differential Revision: D7123795
fbshipit-source-id: fdfae42
Jules Villard