Multi-token names are broken on subsequent expansions when nested in delimiters

Created by: natefaubion

macro (->) {
  rule infix { $a:ident | $b:expr } => {
    function($a) { return $b }
  }
}

a = x -> [y -> y]

The -> inside the array is not recognize as a macro name, and dropped due to how binary ops are combined (non-expr lhs drops the operator and lhs), resulting in an obscure error. I believe it isn't recognized as a macro because of how takeLine handles delimiters. It copies the same range to all of its children. The - and > tokens thus get the exact same range (not adjacent) and getName does not recognize it as a compound name.