fn calculate_debuginfo_offset<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>, L: DebugInfoOffsetLocation<'tcx, Bx>>(
    bx: &mut Bx,
    local: Local,
    var: &PerLocalVarDebugInfo<'tcx, Bx::DIVariable>,
    base: L
) -> DebugInfoOffset<L>