evmc: v7

[meowsbits]

Core-geth's ./evmc adoption and implementation is currently pegged at the latest release version of the v6 major series (v6.3.1).

As noted at the EVMC releases page, v7+ introduces support for the Istanbul EVM upgrades. As suggested by its major bump, it establishes a breaking change to the ABI along with quite a few other non-backward-compatible changes (see https://github.com/ethereum/evmc/releases/tag/v7.0.0).

This issue proposes providing support for the v7 series of EVMC.

Related

• PR: Feat/evmc6 #57 Feat/evmc6
• Issue: Support EVMC6 #55 Support EVMC6
• https://github.com/ledgerwatch/turbo-geth/blob/85219b651e3f3b7156ab2250bc6fbcc9a9a5ea0a/core/vm/evmc.go

[meowsbits]

If I remember correctly, one of the limitations for which v6 was selected as the initial adoptee was that both Hera EWASM and SSVM EWASM supported it at the time. I'm not sure if this is still the case.