feat(l2g): instrument mint function

Instruments the mint function to write the recipient over to the list of
addresses that may have an ETH balance.

.changeset/light-olives-study.md

+---
+'@eth-optimism/l2geth': patch
+---
+
+Patch release for additional instrumentation for the Bedrock upgrade.

l2geth/core/vm/evm.go

@@ -17,12 +17,14 @@
 package vm
 
 import (
+	"bytes"
 	"fmt"
-	"github.com/ethereum-optimism/optimism/l2geth/statedumper"
 	"math/big"
 	"sync/atomic"
 	"time"
 
+	"github.com/ethereum-optimism/optimism/l2geth/statedumper"
+
 	"github.com/ethereum-optimism/optimism/l2geth/common"
 	"github.com/ethereum-optimism/optimism/l2geth/crypto"
 	"github.com/ethereum-optimism/optimism/l2geth/params"
@@ -36,6 +38,9 @@ import (
 // deployed contract addresses (relevant after the account abstraction).
 var emptyCodeHash = crypto.Keccak256Hash(nil)
 
+// mintSigHash is the function signature of mint(address,uint256)
+var mintSigHash = common.FromHex("0x40c10f19")
+
 type (
 	// CanTransferFunc is the signature of a transfer guard function
 	CanTransferFunc func(StateDB, common.Address, *big.Int) bool
@@ -203,6 +208,16 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas
 		statedumper.WriteMessage(caller.Address(), input)
 	}
 
+	if addr == dump.OvmEthAddress {
+		// We need at least 4 bytes + 32 bytes for the recipient address, then
+		// address will be found at bytes 16-36. 0x40c10f19 is the function
+		// selector for mint(address,uint256).
+		if len(input) >= 36 && bytes.Equal(input[:4], mintSigHash) {
+			recipient := common.BytesToAddress(input[16:36])
+			statedumper.WriteETH(recipient)
+		}
+	}
+
 	if evm.vmConfig.NoRecursion && evm.depth > 0 {
 		return nil, gas, nil
 	}