Export types.rlpHash -> types.RLPHash

This is because one of its consumers (types.Header) will move out of
the types package.

core/types/block.go

@@ -113,7 +113,7 @@ type headerMarshaling struct {
 // Hash returns the block hash of the header, which is simply the keccak256 hash of its
 // RLP encoding.
 func (h *Header) Hash() common.Hash {
-	return rlpHash(h)
+	return RLPHash(h)
 }
 
 // Size returns the approximate memory used by all internal contents. It is used
@@ -145,7 +145,8 @@ func (h *Header) GetShardState() (shard.ShardState, error) {
 	return shardState, nil
 }
 
-func rlpHash(x interface{}) (h common.Hash) {
+// RLPHash hashes the RLP representation of the given object.
+func RLPHash(x interface{}) (h common.Hash) {
 	hw := sha3.NewLegacyKeccak256()
 	rlp.Encode(hw, x)
 	hw.Sum(h[:0])
@@ -453,7 +454,7 @@ func (c *writeCounter) Write(b []byte) (int, error) {
 
 // CalcUncleHash returns rlp hash of uncles.
 func CalcUncleHash(uncles []*Header) common.Hash {
-	return rlpHash(uncles)
+	return RLPHash(uncles)
 }
 
 // WithSeal returns a new block with the data from b but the header replaced with

core/types/transaction.go

@@ -292,7 +292,7 @@ func (tx *Transaction) Hash() common.Hash {
 	if hash := tx.hash.Load(); hash != nil {
 		return hash.(common.Hash)
 	}
-	v := rlpHash(tx)
+	v := RLPHash(tx)
 	tx.hash.Store(v)
 	return v
 }

core/types/transaction_signing.go

@@ -157,7 +157,7 @@ func (s EIP155Signer) SignatureValues(tx *Transaction, sig []byte) (R, S, V *big
 // Hash returns the hash to be signed by the sender.
 // It does not uniquely identify the transaction.
 func (s EIP155Signer) Hash(tx *Transaction) common.Hash {
-	return rlpHash([]interface{}{
+	return RLPHash([]interface{}{
 		tx.data.AccountNonce,
 		tx.data.Price,
 		tx.data.GasLimit,
@@ -215,7 +215,7 @@ func (fs FrontierSigner) SignatureValues(tx *Transaction, sig []byte) (r, s, v *
 // Hash returns the hash to be signed by the sender.
 // It does not uniquely identify the transaction.
 func (fs FrontierSigner) Hash(tx *Transaction) common.Hash {
-	return rlpHash([]interface{}{
+	return RLPHash([]interface{}{
 		tx.data.AccountNonce,
 		tx.data.Price,
 		tx.data.GasLimit,