Only run parsing::instructions::tests::test_size on 64-bit targets

[musicinmybrain]

In Fedora, we still build and test Rust library crates on i686 by default due to the existence of multilib packages for x86_64. The addition of #[cfg(any(target_pointer_width = "64", target_pointer_width = "32"))] to cover any other possible pointer widths is pedantic, since this crate will probably never be used on any other pointer width.

An alternative, if you only care about checking the size on 64-bit targets, would be to guard the test with

// Expected size is based on a typical 64-bit target
#[cfg(any(target_pointer_width = "64"))]

and move on.

[Keats]

An alternative, if you only care about checking the size on 64-bit targets,

Yeah let's do that I don't care about 32-bit targets

[musicinmybrain]

Ok, adjusted.