let width = tcx.layout_of(param_ty).map_err(|_| LitToConstError::Reported)?.size;
trace!("trunc {} with size {} and shift {}", n, width.bits(), 128 - width.bits());
let result = truncate(n, width);
let width = tcx.layout_of(param_ty).map_err(|_| LitToConstError::Reported)?.size;
trace!("trunc {} with size {} and shift {}", n, width.bits(), 128 - width.bits());
let result = truncate(n, width);