Builtin operators can't be macros except in the most basic case

Created by: natefaubion

While this will work:

macro ^ {
  rule {} => {
    foo
  }
}
^

If you try to match on anything else:

macro ^ {
  rule { () } => {
    foo()
  }
}
^()

It won't expand the macro, and you end up with a parse error. This only happens with punctuators that are builtin operators. Things like @ and # work fine, obviously.