RFR: 8229337: java.lang.Math class doc should be adjusted regarding -Exact methods

[Julia Boes]

Hi,

This is a minor fix of the javadoc in java.lang.Math. The methods 
decrementExact(), incrementExact() and negateExact()  declare they throw 
a ArithmeticException, and as such should be included in the list of 
operations that can detect overflow in the class-level javadoc.

Bug: https://bugs.openjdk.java.net/browse/JDK-8229337
Webrev: http://cr.openjdk.java.net/~dfuchs/jboes/8229337/webrev.00/

Is a CSR request needed?

Thanks,
Julia