Converts this value to its ASCII upper case equivalent in-place.
ASCII letters 'a' to 'z' are mapped to 'A' to 'Z', but non-ASCII letters are unchanged.
To return a new uppercased value without modifying the existing one,
use [`to_ascii_uppercase`].
[`to_ascii_uppercase`]: Self::to_ascii_uppercase
# Examples
Basic usage:
```
# use ::exint::primitive::*;
# ::exint::uint! {
let mut lowercase_a = u8::from(b'a');
let uppercase_a = u8::from(b'A');
lowercase_a.make_ascii_uppercase();
assert_eq!(uppercase_a, lowercase_a);
# }
```