(S) RFR: 8141024: [Solaris] Obsolete UseAltSigs

[David Holmes]

Bug: https://bugs.openjdk.java.net/browse/JDK-8141024

webrev:


History:

The JVM claimed SIGUSR1 and SIGUSR2 for the INTERRUPT and ASYNC signals, 
respectively.

-Xusealtsigs, mapping to -XX:+UseAltSigs, was provided to allow users to 
reclaim those signals and instead use two of the real-time signals 
(between SIGRTMIN and SIGRTMAX)

As of Solaris 10, Solaris provides SIGJVM1 and SIGJVM2 exclusively for 
the JVMs use. This avoids any conflict with user-defined signal usage.

As of Java 6 we documented that on Solaris 10 
-Xusealtsigs/-XX:+UseAltSigs had no affect:

http://www.oracle.com/technetwork/java/javase/signals-139944.html#gbzbh

As we no longer support Solaris versions older than 10, we do not need 
the UseAltSigs functionality and the flags can be made Obsolete.

Thanks,
David