core/vm: move Log to core/types

This significantly reduces the dependency closure of ethclient, which no
longer depends on core/vm as of this change.

All uses of vm.Logs are replaced by []*types.Log. NewLog is gone too,
the constructor simply returned a literal.

core/vm/instructions.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/math"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/params"
 )
@@ -605,8 +606,14 @@ func makeLog(size int) executionFunc {
 		}
 
 		d := memory.Get(mStart.Int64(), mSize.Int64())
-		log := NewLog(contract.Address(), topics, d, env.BlockNumber.Uint64())
-		env.StateDB.AddLog(log)
+		env.StateDB.AddLog(&types.Log{
+			Address: contract.Address(),
+			Topics:  topics,
+			Data:    d,
+			// This is a non-consensus field, but assigned here because
+			// core/state doesn't know the current block number.
+			BlockNumber: env.BlockNumber.Uint64(),
+		})
 		return nil, nil
 	}
 }