Rollup merge of #121824 - celinval:smir-scalar, r=oli-obk

Implement missing ABI structures in StableMIR

Add implementations for Scalar, Primitive and WrappingRange for StableMIR.

FYI, I thought about reusing the `rustc_abi` module, since it is designed to not necessarily depend on the `rustc` internals, but the maintenance burden to maintain this crate in crates.io doesn't seem worth it at this point.

Fixes rust-lang/project-stable-mir#58

Author: matthiaskrgr