Fuzzing vm_runner next steps

[matklad]

#5462 implements basic vm_runner fuzzing. THere's a bunch of stuff we can do on top, in the order of increasing complexity:

• impl Arbitrary for VMContext
• wip: allow to specify module's interface in wasm-smith bytecodealliance/wasm-tools#286 – allowing fuzzer to exercise host functions
• add some way to diffirentially fuzz two neard binaries against each other. Today, to do diff-fuzz you need to add an extra VM Kind, and thats a chore.

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[stale]

This issue has been automatically marked as stale because it has not had recent activity in the last 2 months.
It will be closed in 7 days if no further activity occurs.
Thank you for your contributions.

[matklad]

This was completed:

• we do differential fuzzing
• we do use host fn

We don't randomize VMContext, but that's not super important I think

@Ekleog do we consider this done?

[Ekleog]

I think so, yes! We still have things like fuzzing host functions, but it's already being tracked in #6500 :)