op-wheel: add cheat code command

Allows it to set into the state arbitrary code at an arbitrary account.
This will make it very easy to patch contracts that contain immutables.
Then we can patch the contracts to have different immutables without
needing to update the proxies and worry about that.

We can also cheat the impl of the multisig to be a call forwarder so
that we do not need to cheat so many storage slots and forget about
particular slots.

op-wheel/cheat/cheat.go

@@ -379,6 +379,13 @@ func SetBalance(addr common.Address, amount *big.Int) HeadFn {
 	}
 }
 
+func SetCode(addr common.Address, code string) HeadFn {
+	return func(headState *state.StateDB) error {
+		headState.SetCode(addr, common.FromHex(code))
+		return nil
+	}
+}
+
 func SetNonce(addr common.Address, nonce uint64) HeadFn {
 	return func(headState *state.StateDB) error {
 		headState.SetNonce(addr, nonce)

op-wheel/commands.go

@@ -271,6 +271,17 @@ var (
 			return ch.RunAndClose(cheat.SetBalance(addrFlagValue("address", ctx), bigFlagValue("balance", ctx)))
 		}),
 	}
+	CheatSetCodeCmd = cli.Command{
+		Name: "code",
+		Flags: []cli.Flag{
+			DataDirFlag,
+			addrFlag("address", "Address to change code of"),
+			cli.StringFlag{Name: "code", Usage: "New code of the account"},
+		},
+		Action: CheatAction(false, func(ctx *cli.Context, ch *cheat.Cheater) error {
+			return ch.RunAndClose(cheat.SetCode(addrFlagValue("address", ctx), ctx.String("code")))
+		}),
+	}
 	CheatSetNonceCmd = cli.Command{
 		Name: "nonce",
 		Flags: []cli.Flag{
@@ -440,6 +451,7 @@ var CheatCmd = cli.Command{
 	Subcommands: []cli.Command{
 		CheatStorageCmd,
 		CheatSetBalanceCmd,
+		CheatSetCodeCmd,
 		CheatSetNonceCmd,
 		CheatOvmOwnersCmd,
 		CheatPrintHeadBlock,