Function __action90

fn __action90(
    cx: &mut ParseCtxt<'_>,
    (_, lo, _): (Location, Location, Location),
    (_, _, _): (Location, Token, Location),
    (_, params, _): (Location, RefineParams, Location),
    (_, _, _): (Location, Token, Location),
    (_, body, _): (Location, Expr, Location),
    (_, hi, _): (Location, Location, Location),
) -> RefineArg