core/tracing: extends tracing.Hooks with OnSystemCallStartV2

[nebojsa94]

This PR extends the Hooks interface with a new method, OnSystemCallStartV2, which takes VMContext as its parameter.

Motivation

By including VMContext as a parameter, the OnSystemCallStartV2 hook achieves parity with the OnTxStart hook in terms of provided insights. This alignment simplifies the inner tracer logic, enabling consistent handling of state changes and internal calls within the same framework.

[holiman]

The context won't be well defined here, missing coinbase and gasprice.

		Coinbase:    evm.Context.Coinbase,
		BlockNumber: evm.Context.BlockNumber,
		Time:        evm.Context.Time,
		Random:      evm.Context.Random,
		GasPrice:    evm.TxContext.GasPrice,
		StateDB:     evm.StateDB,

As for motivation, could you please instead explain the practical reason why you want/need this? The provided motivation is a bit theoretical, imo:

By including VMContext as a parameter, the OnSystemCallStartV2 hook achieves parity with the OnTxStart hook in terms of provided insights. This alignment simplifies the inner tracer logic, enabling consistent handling of state changes and internal calls within the same framework.

[nebojsa94]

Sure, I've responded in a second PR with a practical usecase
#30784 (comment)

[maoueh]

On OnSystemCallStartV2, as the original contributor of OnSystemCall/End, I would be fine on breaking the tracing interface and adjusting the existing call to receive the extra argument. Can be bundled with other "breaking changes" that will come soon (TDD, some changes on VMContext that might lend, etc).

It's of course a personal opinion, I'm quite fine if there is a preference to keep backward compatibility and introduce a OnSystemCallStartV2 version.

[s1na]

The context won't be well defined here, missing coinbase and gasprice.

This is a good catch actually which for me confirms we should remove gas price from vm context and replace it with base fee as per #30809. Although I think coinbase will be available I don't see why it shouldn't be. So IMO it's ok.

On OnSystemCallStartV2, as the original contributor of OnSystemCall/End, I would be fine on breaking the tracing interface and adjusting the existing call to receive the extra argument. Can be bundled with other "breaking changes" that will come soon (TDD, some changes on VMContext that might lend, etc).

I think it's ok and we can add a new method for this. We have to eventually set up a process for making backwards incompatible changes.

[s1na]

LGTM