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

This reverts commit 8b57c49490.

core/vm/intpool.go

@@ -1,49 +0,0 @@
-// Copyright 2017 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-package vm
-
-import "math/big"
-
-var checkVal = big.NewInt(-42)
-
-// intPool is a pool of big integers that
-// can be reused for all big.Int operations.
-type intPool struct {
-	pool *Stack
-}
-
-func newIntPool() *intPool {
-	return &intPool{pool: newstack()}
-}
-
-func (p *intPool) get() *big.Int {
-	if p.pool.len() > 0 {
-		return p.pool.pop()
-	}
-	return new(big.Int)
-}
-func (p *intPool) put(is ...*big.Int) {
-	for _, i := range is {
-		// verifyPool is a build flag. Pool verification makes sure the integrity
-		// of the integer pool by comparing values to a default value.
-		if verifyPool {
-			i.Set(checkVal)
-		}
-
-		p.pool.push(i)
-	}
-}