cranelift: update x64 inst_size_test

[pepyakin]

Running cargo test --all on the latest main (3fa545b) fails on my x86_64 machine, in particular, in the test modified. I am creating this PR to check my sanity. I expect the CI for this PR to fail.

[pepyakin]

Yep, it does.

[cfallin]

Out of curiosity, were you seeing issues with a nightly compiler, or something else (local changes, etc)?

[afonso360]

I ran into this issue as well, I think I tried the nightly compiler and it started failing, reverting back to stable works. (This was a few days ago so I'm not totally sure on the details)

[pepyakin]

Oh, yeah, I also thought it's nightly misbehaving, but running

rustup run --install stable cargo test -p cranelift-codegen -- isa::x64::inst::inst_size_test

resulted in the same panic! (rustc 1.64.0 (a55dd71d5 2022-09-19))

[afonso360]

That's weird, I tried updating my stable version, and I'm now on:

stable-x86_64-pc-windows-msvc (default)
rustc 1.64.0 (a55dd71d5 2022-09-19)

And running cargo +stable test -p cranelift-codegen -- isa::x64::inst::inst_size_test passes the test for me. 🤔

Edit: cargo +nightly test -p cranelift-codegen -- isa::x64::inst::inst_size_test does fail the test.

[lqd]

Could it be from the new enum layout from rust-lang/rust#94075 ?

[jameysharp]

We're merging an identical patch now in #5188. I'm glad you all brought this up early so it wasn't a surprise!