[ER] Propose the use of XX::MAX instead of -1 for unsigned integers

[leonardo-m]

Another of those little enhancement suggestions. This code:

fn main() {
    let x: u32 = -1;
}

With rustc 1.48.0-nightly gives this error message:

error[E0600]: cannot apply unary operator `-` to type `u32`
 --> ...\temp.rs:2:18
  |
2 |     let x: u32 = -1;
  |                  ^^ cannot apply unary operator `-`
  |
  = note: unsigned values cannot be negated

I suggest to modify the note, to suggest that u32::MAX may be desired instead, because in C code often you see people use -1 to get the max unsigned value.

[varkor]

This is related to (or possibly a duplicate of) #76413.