core/evm: RANDOM opcode (EIP-4399) (#24141)

* core: implement eip-4399 random opcode

* core: make vmconfig threadsafe

* core: miner: pass vmConfig by value not reference

* all: enable 4399 by Rules

* core: remove diff (f)

* tests: set proper difficulty (f)

* smaller diff (f)

* eth/catalyst: nit

* core: make RANDOM a pointer which is only set post-merge

* cmd/evm/internal/t8ntool: fix t8n tracing of 4399

* tests: set difficulty

* cmd/evm/internal/t8ntool: check that baserules are london before applying the merge chainrules

core/genesis.go

@@ -294,7 +294,7 @@ func (g *Genesis) ToBlock(db ethdb.Database) *types.Block {
 	if g.GasLimit == 0 {
 		head.GasLimit = params.GenesisGasLimit
 	}
-	if g.Difficulty == nil {
+	if g.Difficulty == nil && g.Mixhash == (common.Hash{}) {
 		head.Difficulty = params.GenesisDifficulty
 	}
 	if g.Config != nil && g.Config.IsLondon(common.Big0) {