Code Review Request, 8152237 Support BigInteger.TWO

[Xuelei Fan]

Hi,

Please review the update for the supporting of BigInteger.TWO:

    http://cr.openjdk.java.net/~xuelei/8152237/webrev/

BigInteger.valueOf(2) is a common BigInteger value used in binary and 
cryptography operation calculation.  The BigInteger.TWO is not exported, 
and hence BigInteger.valueOf(2) is used instead in applications and JDK 
components.  The export of static BigInteger.TWO can improve performance 
and simplify existing code.

Thanks,
Xuelei