RFR JDK-8166261: Scanner.nextInt(int) (and similar methods) throws PatternSyntaxException

[Xueming Shen]

Hi

Please help review
issue:  https://bugs.openjdk.java.net/browse/JDK-8166261
webre: http://cr.openjdk.java.net/~sherman/8166261/webrev

The radix sanity check are missing  from 
hasNextByte/Short/Int/Long/BigInteger().
The only method we are doing now is useRadix(). The proposed change here 
is to
add the check into all above methods that take a radix.

Arguably it's an incompatible api change, but I don't expect it really 
breaks anyone's
code.  Need go through ccc if approved.

Thanks,
Sherman