@type addr() :: nil | :unnamed_addr | :local_unnamed_addr

@type linkage() ::
  nil
  | :private
  | :internal
  | :available_externally
  | :linkonce
  | :weak
  | :common
  | :appending
  | :extern_weak
  | :linkonce_odr
  | :weak_odr
  | :external

@type t() :: %Wyvern.GlobalVariable{
  addr: addr(),
  initializer: Wyvern.Value.t() | nil,
  linkage: linkage(),
  mutable: boolean(),
  name: String.t(),
  type: Wyvern.Type.t(),
  visibility: visibility()
}

@type visibility() :: nil | :default | :hidden | :protected