Aria Desires

@bjorn3 it's possible the latest main is less prone to hard aborting? unfortunately I don't have a repro of this issue on my own systems.

Ah cool I can reproduce this on my computer with: ``` rustup toolchain add nightly rustup component add rustc-codegen-cranelift-preview --toolchain nightly rustup override set nightly abi-cafe --add-rustc-codegen-backend=cranelift:cranelift --toolchains=cranelift ```

Aha it's OptionU128 that illegals

Specifically: ``` cargo run --release -- --add-rustc-codegen-backend=cranelift:cranelift --toolchains=cranelift,rustc --tests=OptionU128 --pairs=cranelift_calls_rustc,rustc_calls_cranelift --reprs=rust --conventions=rust ``` That is, both of these sigill: ``` OptionU128::conv_rust::repr_rust::cranelift_calls_rustc OptionU128::conv_rust::repr_rust::rustc_calls_cranelift ```

Ok yes so! This runs the suite to completion with no aborts: ``` if is_rust && test.test == "OptionU128" { result.run = Link; } ``` This sigills: ``` if is_rust...

NB: i recommend just marking this test as "skip" for now

Wow ok #11 was easier than I thought, I've got it locally and spitting out stuff like this 

* https://github.com/Gankra/abi-cafe/pull/67

New main should hopefully no longer have chaos aborts?

pc-windows-gnu eh... I definitely don't run that in my CI and don't have that setup locally... hmm...