Revert "params: core, core/vm, miner: 64bit gas instructions (#3514)"

This reverts commit 8b57c49490.

core/bench_test.go

@@ -92,7 +92,6 @@ func genValueTx(nbytes int) func(int, *BlockGen) {
 var (
 	ringKeys  = make([]*ecdsa.PrivateKey, 1000)
 	ringAddrs = make([]common.Address, len(ringKeys))
-	bigTxGas  = new(big.Int).SetUint64(params.TxGas)
 )
 
 func init() {
@@ -112,8 +111,8 @@ func genTxRing(naccounts int) func(int, *BlockGen) {
 	return func(i int, gen *BlockGen) {
 		gas := CalcGasLimit(gen.PrevBlock(i - 1))
 		for {
-			gas.Sub(gas, bigTxGas)
-			if gas.Cmp(bigTxGas) < 0 {
+			gas.Sub(gas, params.TxGas)
+			if gas.Cmp(params.TxGas) < 0 {
 				break
 			}
 			to := (from + 1) % naccounts
@@ -121,7 +120,7 @@ func genTxRing(naccounts int) func(int, *BlockGen) {
 				gen.TxNonce(ringAddrs[from]),
 				ringAddrs[to],
 				benchRootFunds,
-				bigTxGas,
+				params.TxGas,
 				nil,
 				nil,
 			)