[parser] cleanup: remove unnecessary let rec ... and in class parsing
[parser] cleanup: remove unnecessary let rec ... and in class parsing

Summary:
just reordering stuff to get rid of `let rec`.

aside from just feeling simpler this way, i try to avoid them whenever possible because js_of_ocaml sometimes (always?) handles them suboptimally.

Reviewed By: gabelevi

Differential Revision: D18428420

fbshipit-source-id: 8b46c82d479e4c779a858de54014628556dde095

nmote/flow,nmote/flow,nmote/flow,nmote/flow,nmote/flow,nmote/flow,nmote/flow