cmd/geth, core, eth: implement Constantinople override flag (#18273)

* geth/core/eth: implement constantinople override flag

* les: implemnent constantinople override flag for les clients

* cmd/geth, eth, les: fix typo, move flag to experimentals

cmd/geth/config.go

@@ -21,6 +21,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"math/big"
 	"os"
 	"reflect"
 	"unicode"
@@ -152,7 +153,9 @@ func enableWhisper(ctx *cli.Context) bool {
 
 func makeFullNode(ctx *cli.Context) *node.Node {
 	stack, cfg := makeConfigNode(ctx)
-
+	if ctx.GlobalIsSet(utils.ConstantinopleOverrideFlag.Name) {
+		cfg.Eth.ConstantinopleOverride = new(big.Int).SetUint64(ctx.GlobalUint64(utils.ConstantinopleOverrideFlag.Name))
+	}
 	utils.RegisterEthService(stack, &cfg.Eth)
 
 	if ctx.GlobalBool(utils.DashboardEnabledFlag.Name) {

cmd/geth/main.go

@@ -123,6 +123,7 @@ var (
 		utils.RinkebyFlag,
 		utils.VMEnableDebugFlag,
 		utils.NetworkIdFlag,
+		utils.ConstantinopleOverrideFlag,
 		utils.RPCCORSDomainFlag,
 		utils.RPCVirtualHostsFlag,
 		utils.EthStatsURLFlag,