[Unity][TVMScript] Register the dispatch for runtime::Module

[sunggg]

This PR registers the dispatch for runtime::Module so that we can print IRModule with BYOC runtime after RunCodegen pass.

cc. @yelite @junrushao

[tvm-bot]

Thanks for contributing to TVM! Please refer to the contributing guidelines https://tvm.apache.org/docs/contribute/ for useful information and tips. Please request code reviews from Reviewers by @-ing them in a comment.

• cc @Hzfengsy, @junrushao, @quic-sanirudh, @shingjan _{See #10317 for details}

_{Generated by tvm-bot}

[Hzfengsy]

One generic problem: can runtime::Module roundtrip-able print and parse if we printed it as a string? One alternate solution is printed it as metadata.

Love to hear more opinions from the community. cc @junrushao @cyx-6

[junrushao]

I don't think it's roundtrippable, and additionally, there is no guarantee that it's serializable, which means even if we print it as metadata it's not guaranteed to be parsed back

[tqchen]

I think this is something we need to discuss a bit further before taking actions. We should have specific categorizations of runtime modules. Let us followup in community meeting and forums.

At a high level, we can categorize the runtime module properties:

• binary exportable
• binary serializable
• dso exportable
• runnable

Then we can find ways to be able to serialize the modules that are binary serializable and report error for the rest if we want to have strict serialization.

[junrushao]

I am not sure if making runtime::Module as roundtrippable as possible is a goal in this particular PR, as it primarily aims to make it "printable" not "parsable" :-)

[slyubomirsky]

If roundtripping is not intended, we should communicate that clearly, since that would definitely be what users would expect otherwise. (Principle of least surprise.)

[tqchen]

I think we can close this for now, following by a more robust solution that detects binary serializable modules and only serialize those(perhaps via base64 encoding)

[tqchen]

#14406

[sunggg]

Sounds good to me. Will create the new PR with this change #14406. Thank you all for the review and suggestions!