chore: bump rust to latest stable

[gjermundgaraba]

No description provided.

[eloylp]

Hi @webmaster128 - apologies for the direct ping.

At Eiger, we’re currently building a Solana <-> Axelar bridge. Since the Axelar network uses CosmWasm smart contracts, we need to include certain Solana dependencies that require the latest stable Rust version.

This PR is currently a blocker for us, and we’d greatly appreciate it if it could be reviewed and merged soon. A new release including this change would unblock our integration work.

Thanks a lot in advance, and happy to provide any additional info if needed!

[chipshort]

@eloylp This cannot currently be merged because it is blocked by CosmWasm/cosmwasm#2292. We are currently waiting for a Wasmer release that has full reference-types support because latest Rust enforces having this.

[chipshort]

Alternatively, it might be possible to use latest Rust here and get rid of the problematic call_indirect instruction encoding afterwards in some way. This Rust issue about the topic suggests running through wasm2wat and wat2wasm, but that doesn't seem to be a lossless translation. For example, we use a custom section in the wasm for the migrate_version feature, which doesn't seem to be preserved in the text format.
So this would probably require a more targeted approach.

edit: Actually, it might be possible to disable reference types using some compiler flag? That would be much easier.

[Kayanski]

Is it possible to move this now that CosmWasm/cosmwasm#2292 has been merged ?
thank you !

[chipshort]

Hi @Kayanski! Yes, this can in principle be pushed forward now. But please note that the issue fix is not released yet and requires the chains to upgrade to it, so it will take some time until a new Rust version can actually be used for contracts in production.
I will bump it to 1.86 (we're having similar problems with 1.87 atm), but I would only release the optimizer image when CosmWasm 3.0 is out, so it can actually be used.

[chipshort]

Closing in favor of #168