[8u20] RFR (XS) 8046516: Segmentation fault in JVM (easily reproducible)

[Vladimir Kozlov]

8u20 backport request. The fix was pushed into jdk9 yesterday and nightly testing shows no related problems.

Changes from jdk9 applied to 8u without conflicts.

http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/455be7c3df86
http://cr.openjdk.java.net/~kvn/8046516/webrev/
https://bugs.openjdk.java.net/browse/JDK-8046516

Thanks,
Vladimir