Casting negative literals to unsigned doesn't work

[shuklaayush]

Aim

I use -1 as u{X} syntax to get the unsigned max values. This doesn't seem to work in the new ssa.

use dep::std::println;

#[test]
fn test_cast() {
    let a: u8 = -1 as u8;
    // "0x30644e72e131a029b85045b68181585d2833e84879b9709143e1f593f0000000"
    println(a);
    // assert(a == 0xff);
}

Expected Behavior

The above code should print out 0xff instead of MODULUS - 1

Bug

The test should pass

A workaround for now is to replace -1 as u8 with 0-1 as u8

To Reproduce

1. Copy the code above
2. Run nargo test

Installation Method

Compiled from source

Nargo Version

nargo 0.9.0 (git version hash: 66cb1fd, is dirty: false)

Additional Context

No response

Would you like to submit a PR for this Issue?

Maybe

Support Needs

No response

[kevaundray]

@Ethan-000 have assigned this to you, if you have questions please ask them in here.

bumping @jfecher for visibility

[jfecher]

I would think this should be handled by
https://github.com/noir-lang/noir/blob/master/crates/noirc_evaluator/src/ssa_refactor/ir/instruction.rs#L369-L377 but it seems like it is not