Preserve content after trailing line comments

Summary: Make the formatter inline continuation spacing consult trailing line comments generically instead of special-casing fields. When a printed token owns a //-style trailing comment, following inline content moves to the next line so fields, typedefs, consts, includes, namespaces, services, enum values, annotations, and function signatures do not get swallowed into the comment text.

Reviewed By: hchokshi

Differential Revision: D110081313

fbshipit-source-id: 075b493b3266986309b5bdd4c1097d9280ba1b9f

Author: iahs