RFR(XS): 8193308: Disallow installing user signal handlers for SIGBUS on OSX

[Robin Westberg]

Hi all,

Please review the following change to disallow installing user signal handlers for SIGBUS on OSX. On OSX, SIGBUS is used internally by the VM (where most other platforms only use SIGSEGV), and installing a user handler can lead to a deadlock.

Issue: https://bugs.openjdk.java.net/browse/JDK-8193308 <https://bugs.openjdk.java.net/browse/JDK-8193308>
Webrev: http://cr.openjdk.java.net/~rwestberg/8193308/webrev.00/ <http://cr.openjdk.java.net/~rwestberg/8193308/webrev.00/>
Testing: hs-tier1, hs-tier2

Best regards,
Robin