[8u20] RFR (S) 8038633: crash in VM_Version::get_processor_features() on startup

[Vladimir Kozlov]

8u20 backport request. These changes were pushed into jdk9 2 days ago 
and nightly testing shows no problems.

Changes from jdk9 applied to 8u without conflicts.

http://cr.openjdk.java.net/~kvn/8038633/webrev.01/
http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/be5c9920f0e1
https://bugs.openjdk.java.net/browse/JDK-8038633

Thanks,
Vladimir