[8u40] backport RFR(S) 8065618: C2 RA incorrectly removes kill projections

[Vladimir Kozlov]

8u40 backport request.  Changes were pushed into jdk9 more then week 
ago, no problems were found since then. Changes are NOT applied to 8u 
cleanly because of RA code refactoring in jdk9.

http://cr.openjdk.java.net/~kvn/8065618_8u/webrev/

jdk9:

http://cr.openjdk.java.net/~kvn/8065618/webrev/
https://bugs.openjdk.java.net/browse/JDK-8065618
http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/2aa1a6c41461

Thanks,
Vladimir