===========================
Designator - Identifier
===========================
alias a is b;
---

(design_file
  (alias_declaration
    designator: (identifier)
    denotator: (simple_name)))

==============================
Designator - Character literal
==============================
alias '0' is STD.STANDARD.'0' [return STD.STANDARD.BIT];
---

(design_file
  (alias_declaration
    designator: (character_literal)
    denotator: (selected_name
      prefix: (selected_name
        prefix: (simple_name)
        suffix: (simple_name))
      suffix: (character_literal))
    (signature
      (return
        (type_mark
          (selected_name
            prefix: (selected_name
              prefix: (simple_name)
              suffix: (simple_name))
            suffix: (simple_name)))))))

==============================
Designator - Operator symbol
==============================
alias "or" is STD.STANDARD."or" [STD.STANDARD.BIT,
                                 STD.STANDARD.BIT
                          return STD.STANDARD.BIT];
---

(design_file
  (alias_declaration
    designator: (operator_symbol)
    denotator: (selected_name
      prefix: (selected_name
        prefix: (simple_name)
        suffix: (simple_name))
      suffix: (operator_symbol))
    (signature
      (type_mark
        (selected_name
          prefix: (selected_name
            prefix: (simple_name)
            suffix: (simple_name))
          suffix: (simple_name)))
      (type_mark
        (selected_name
          prefix: (selected_name
            prefix: (simple_name)
            suffix: (simple_name))
          suffix: (simple_name)))
      (return
        (type_mark
          (selected_name
            prefix: (selected_name
              prefix: (simple_name)
              suffix: (simple_name))
            suffix: (simple_name)))))))
