message: op-chain-ops: default `L2Addresses`
  For building a developer genesis, if the `L2Addresses` struct
  is `nil`, it will now use the default values. This simplifies
  config and reduces code duplication as `nil` can now be passed.
diff: package genesis
  import (
  + "github.com/ethereum-optimism/optimism/op-bindings/predeploys"
  "github.com/ethereum-optimism/optimism/op-chain-ops/state"
  "github.com/ethereum/go-ethereum/common"
  "github.com/ethereum/go-ethereum/core/types"
  @@ -29,6 +30,14 @@ func BuildL2DeveloperGenesis(config *DeployConfig, l1StartBlock *types.Block, l2
  }
  SetPrecompileBalances(db)
  + if l2Addrs == nil {
  + l2Addrs = &L2Addresses{
  + ProxyAdmin: predeploys.DevProxyAdminAddr,
  + L1StandardBridgeProxy: predeploys.DevL1StandardBridgeAddr,
  + L1CrossDomainMessengerProxy: predeploys.DevL1CrossDomainMessengerAddr,
  + }
  + }
  +
  return BuildL2Genesis(db, config, l1StartBlock, l2Addrs)
  }
  