Parser: Discuss and fix TODOs in Parser2 and Weeder2

[magnus-madsen]

Parser2:

• TODO: There is a performance penalty from doing it this way since this insert is O(n).
• TODO: if the actual kind was a comment, we should produce a "Invalid comment" error instead.
• TODO: Static is used as a type in Prelude.flix. Should we allow this?
  • MM: Yes, static may be a keyword, but Static is not. So it should be fine, right?
• TODO: Pure and Impure are used in enums as tags in Prelude.flix. Should we allow this?
  • MM: Impure is not a keyword anymore, right?
  • MM: The Pure case presents a problem.
• TODO: It's common to type '=' instead of '=>' here. Should we make a specific error?
  • Remove TODO, create new ticket with ideas in that ticket.
• TODO: It's common to type '=' instead of '=>' here. Should we make a specific error?
  • Remove TODO, create new ticket with ideas in that ticket.
• TODO: Static is used as a type name in Prelude.flix. That requires special handling here.
  • I think it should not? Since its not a keyword.

Weeder2:

• TODO: There is a Declaration.Law but old Weeder produces a Def
  • MM: Let us remove Declaration.Law then.
• TODO: Doc comments on enum cases. It is not available on [[Case]] yet.
  • MM: Add it.
• TODO: Doc comments on enum cases. It is not available on [[Case]] yet.
  • MM: Add it.
• TODO: there is no Ast.Modifier for 'inline'
  • MM: Remove all support for inline. It does not exist.
• TODO EFF-MIGRATION create dedicated Impure type
  • MM: ???
• TODO: This double reports the same error. We should be able to handle this resiliently if we had JvmOp.Error.