Add ci job for simd models tests, with logging of rng seed.

[maximebuyse]

This PR addresses part of the feedback in the PR to the upstream repo:

• Adding a CI job to run our tests (Testable Models for SIMD Intrinsics model-checking/verify-rust-std#423 (review))
• Logging the seed used by the rng (Testable Models for SIMD Intrinsics model-checking/verify-rust-std#423 (comment))

I also added some logging of input value on assertion failures which might also be useful to debug test failures.

[maximebuyse]

@W95Psp I am interested in your feedback on this, especially about my implementation using mutex and static for having the same rng everywhere (which is necessary to ensure reproducibility from the seed we log.