[8u20] RFR (XS) 8041351: Crash in src/share/vm/opto/loopnode.cpp:3215 - assert(!had_error) failed: bad dominance

[Vladimir Kozlov]

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

Changes from jdk9 applied to 8u without conflicts.

http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/4bc3f8fa071f
https://bugs.openjdk.java.net/browse/JDK-8041351

Thanks,
Vladimir