CPPO directive break the flow in OCaml

[giraud]

plugin version: 0.119

Description

Incorrect parsing when using a #if directive, it should be 'transparent' to the parser

code

let _ = match x with
  | false -> None
  #if OCAML_MAJOR = 5
  | true -> Some(5)
  #elif OCAML_MAJOR = 4 && OCAML_MINOR = 6
  | true -> Some(4)
  #endif