Inline parse_const_or_type_const_declaration and fix node creation order

Summary:
With smart constructors we care about node creation order and not only how are they used.

In this case `parse_const_or_type_const_declaration` was accepting pre-created `abstract` node, but then depending on tokens ahead we create node for missing visibility specification that should go before `abstract`.

To fix this I inlined all the calls to `parse_const_or_type_const_declaration` and just increased lookahead in the use-sites.

Differential Revision: D7124423

fbshipit-source-id: ea1c9262847acd667e41afa9b8b2616f2f3f739c

hphp/hack/src/parser/full_fidelity_declaration_parser.ml

@@ -625,24 +625,38 @@ module WithExpressionAndStatementAndTypeParser
    children ... ;

  *)
    let token = peek_token parser in
    match (Token.kind token) with
    match peek_token_kind parser with
    | Children -> parse_xhp_children_declaration parser
    | Category -> parse_xhp_category_declaration parser
    | Use -> parse_trait_use parser
    | Const ->
      let (parser, missing) = Make.missing parser (pos parser) in
      parse_const_or_type_const_declaration parser missing
      begin
        let (parser, missing) = Make.missing parser (pos parser) in
        let kind1 = peek_token_kind ~lookahead:1 parser in
        let kind2 = peek_token_kind ~lookahead:2 parser in
        match kind1, kind2 with
        | Type, Semicolon ->
          let (parser, missing') = Make.missing parser (pos parser) in
          let (parser, const) = assert_token parser Const in
          parse_const_declaration parser missing missing' const
        | Type, _ when kind2 <> Equal ->
          let (parser, const) = assert_token parser Const in
          parse_type_const_declaration parser missing const
        | _, _ ->
          let (parser, missing') = Make.missing parser (pos parser) in
          let (parser, const) = assert_token parser Const in
          parse_const_declaration parser missing missing' const
      end
    | Abstract -> parse_methodish_or_const_or_type_const parser
    | Public
    | Protected
    | Private ->
      let (parser1, visibility) = next_token parser in
      let next_kind = peek_token_kind parser1 in
      if next_kind = Const then
        let (parser, const) = assert_token parser1 Const in
        let (parser, visibility) = Make.token parser visibility in
        let (parser, visibility) = Make.token parser1 visibility in
        let (parser, missing) = Make.missing parser (pos parser) in
        let (parser, const) = assert_token parser Const in
        parse_const_declaration parser visibility missing const
      else
        let (parser, missing) = Make.missing parser (pos parser) in
@@ -1133,20 +1147,6 @@ module WithExpressionAndStatementAndTypeParser
      let (parser, semi) = require_semicolon parser in
      Make.trait_use parser use_token trait_name_list semi

  and parse_const_or_type_const_declaration parser abstr =
    let (parser, const) = assert_token parser Const in
    let kind1 = peek_token_kind parser in
    let kind2 = peek_token_kind ~lookahead:1 parser in
    match kind1, kind2 with
    | Type, (Equal | Semicolon) ->
      let (parser, missing) = Make.missing parser (pos parser) in
      parse_const_declaration parser missing abstr const
    | Type, _ when kind2 <> Equal ->
      parse_type_const_declaration parser abstr const
    | _, _ ->
      let (parser, missing) = Make.missing parser (pos parser) in
      parse_const_declaration parser missing abstr const

  and parse_property_declaration ?(contains_abstract=false) parser modifiers =
    (* SPEC:
        property-declaration:
@@ -1675,9 +1675,24 @@ module WithExpressionAndStatementAndTypeParser
        final
   *)
  and parse_methodish_or_const_or_type_const parser =
    let (parser1, abstract) = assert_token parser Abstract in
    if peek_token_kind parser1 = Const then
      parse_const_or_type_const_declaration parser1 abstract
    if peek_token_kind ~lookahead:1 parser = Const then
      let kind1 = peek_token_kind ~lookahead:2 parser in
      let kind2 = peek_token_kind ~lookahead:3 parser in
      match kind1, kind2 with
      | Type, Semicolon ->
        let (parser, missing) = Make.missing parser (pos parser) in
        let (parser, abstr) = assert_token parser Abstract in
        let (parser, const) = assert_token parser Const in
        parse_const_declaration parser missing abstr const
      | Type, _ when kind2 <> Equal ->
        let (parser, abstr) = assert_token parser Abstract in
        let (parser, const) = assert_token parser Const in
        parse_type_const_declaration parser abstr const
      | _, _ ->
        let (parser, missing) = Make.missing parser (pos parser) in
        let (parser, abstr) = assert_token parser Abstract in
        let (parser, const) = assert_token parser Const in
        parse_const_declaration parser missing abstr const
    else
      let (parser, modifiers, _) = parse_modifiers parser in
      let (parser, missing) = Make.missing parser (pos parser) in