`const LE_I128` needs parentheses to negate the value *before* calling
`to_le()`, otherwise it doesn't match the operations performed in the
black-boxed part of the test. This only makes a tangible difference on
big-endian targets.
#[cfg(not(target_arch = "asmjs"))]
{
const BE_U128: u128 = 999999u128.to_be();
- const LE_I128: i128 = -999999i128.to_le();
+ const LE_I128: i128 = (-999999i128).to_le();
assert_eq!(BE_U128, b(999999u128).to_be());
assert_eq!(LE_I128, b(-999999i128).to_le());
}