Returns the number of leading zeros in the binary representation of `self`.
Depending on what you're doing with the value, you might also be interested in the
[`ilog2`] function which returns a consistent number, even if the type widens.
[`ilog2`]: Self::ilog2
# Examples
Basic usage:
```
# use ::exint::primitive::*;
# ::exint::uint! {
assert_eq!((-1_i24).leading_zeros(), 0);
# }
```