Add support for the volatile_set_memory intrinsic

[niluxv]

Add support for the unstable volatile_set_memory intrinsic

(Runtime behaviour and soundness requirements for volatile_set_memory are identical to those of write_bytes, so supporting this intrinsic is trivial.)

[RalfJung]

Thanks for the PR!

Could you extend the tests in tests/run-pass/write-bytes.rs to also call the new intrinsic?

[niluxv]

I wonder whether volatile.rs is a better location or not (on the one hand it already has #![feature(core_intrinsics)], but on the other hand the test can be nearly identical to the tests already in write-bytes.rs)... ?

[RalfJung]

Hm, good point... no strong opinion.

[RalfJung]

This seems fine for now though. Thanks!

@bors r+

[bors]

📌 Commit 083e5e6 has been approved by RalfJung

[bors]

⌛ Testing commit 083e5e6 with merge 94ae910...

[bors]

☀️ Test successful - checks-actions
Approved by: RalfJung
Pushing 94ae910 to master...