Amsterdam devnet3: EIP-8037 state gas (reservoir model)

[rakita]

Summary

Implements EIP-8037 state gas using the reservoir model for Amsterdam devnet3. This is a major change to how gas accounting works in revm.

Core changes

• GasTracker struct (context/interface/src/cfg/gas.rs): New centralized gas tracker with remaining, reservoir, state_gas_spent, and refunded fields. The reservoir holds execution gas exceeding TX_MAX_GAS_LIMIT, creating a separate budget for state gas operations.
• Gas struct updated (interpreter/src/gas.rs): Delegates to GasTracker internally. Adds record_state_cost() (draws from reservoir first, then spills to remaining) alongside existing record_cost() for regular gas. The GAS opcode returns only remaining (excludes reservoir per EIP-8037).
• GasParams / GasId (context/interface/src/cfg/gas_params.rs): New parameterized gas cost system with GasId constants (1-45) and GasParams::get(GasId) lookup, replacing some hardcoded gas values.
• ResultGas (context/interface/src/result.rs): Extended to carry state_gas_spent and reservoir through execution results, enabling proper gas accounting in receipts and post-execution.

Handler changes

• Frame gas propagation (handler/src/frame.rs): Child frames receive reservoir from parent. On return, parent absorbs child's reservoir and accumulates state_gas_spent.
• Pre-execution (handler/src/pre_execution.rs): EIP-7702 auth list state gas split into separate accounting via split_eip7702_refund().
• Post-execution (handler/src/post_execution.rs): Floor gas (EIP-7623) and refund cap calculations updated to work with reservoir model. State gas spent excluded from regular refund caps.
• Validation (handler/src/validation.rs): Transaction validation updated for state gas budget.
• System calls (handler/src/system_call.rs): Gas handling updated for reservoir model.

Instruction changes

• SSTORE (interpreter/src/instructions/host.rs): State gas charging for storage writes.
• CREATE/CREATE2 (interpreter/src/instructions/contract.rs): State gas for code deposit and contract creation. Static call check ordering aligned with execution-specs generic_create().
• CALL variants (interpreter/src/instructions/contract/call_helpers.rs): State gas for account creation (value transfer to new accounts).
• SELFDESTRUCT (interpreter/src/instructions/system.rs): State gas for beneficiary account creation.

Precompile changes

• Simplified interface (precompile/src/interface.rs): Removed gas_limit from PrecompileOutput, flattened PrecompileError.
• PrecompileProvider (handler/src/precompile_provider.rs): Updated for reservoir handling.

op-revm

• Updated handler.rs and precompiles.rs to work with the new gas model.

Testing

• 37 EIP-8037 test fixtures covering: SSTORE (new/overwrite/clear/refund), CALL (new/existing account, value transfer), CREATE/CREATE2 (code deposit, size limits), SELFDESTRUCT, nested frames, reservoir refill on revert/halt, gas opcode behavior, block gas limits, and regular gas cap scenarios.
• ~2000 lines of test code in ee-tests/src/eip8037.rs.

Devnet3-specific adjustments

Two reverts from the full spec implementation to match devnet3 behavior:

• Reservoir is not restored on revert/halt (state gas consumed is final regardless of outcome)
• CREATE/CREATE2 static call check happens after gas charging (matches execution-specs ordering)

Test plan

• cargo nextest run --workspace
• cargo clippy --workspace --all-targets --all-features
• Ethereum state tests via cargo run -p revme statetest
• no_std compatibility check
• EIP-8037 specific tests: cargo test -p ee-tests eip8037

[codspeed-hq]

Merging this PR will degrade performance by 3.31%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

❌ 1 regressed benchmark
✅ 176 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	EXTCODESIZE_50	39 µs	40.3 µs	-3.31%

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_{Comparing devnet3 (517d9c8) with main (910c632)}