core/vm, params: implement EXTCODEHASH opcode (#17202)

* core/vm, params: implement EXTCODEHASH opcode

* core, params: tiny fixes and polish

* core: add function description

params/gas_table.go

@@ -20,6 +20,7 @@ package params
 type GasTable struct {
 	ExtcodeSize uint64
 	ExtcodeCopy uint64
+	ExtcodeHash uint64
 	Balance     uint64
 	SLoad       uint64
 	Calls       uint64
@@ -63,7 +64,7 @@ var (
 		CreateBySuicide: 25000,
 	}
 	// GasTableEIP158 contain the gas re-prices for
-	// the EIP15* phase.
+	// the EIP155/EIP158 phase.
 	GasTableEIP158 = GasTable{
 		ExtcodeSize: 700,
 		ExtcodeCopy: 700,
@@ -73,6 +74,20 @@ var (
 		Suicide:     5000,
 		ExpByte:     50,
 
+		CreateBySuicide: 25000,
+	}
+	// GasTableConstantinople contain the gas re-prices for
+	// the constantinople phase.
+	GasTableConstantinople = GasTable{
+		ExtcodeSize: 700,
+		ExtcodeCopy: 700,
+		ExtcodeHash: 400,
+		Balance:     400,
+		SLoad:       200,
+		Calls:       700,
+		Suicide:     5000,
+		ExpByte:     50,
+
 		CreateBySuicide: 25000,
 	}
 )