[12] RFR: 8211698: Crash in C2 compiled code

[Rahul Raghavan]

Hi,

Please review the following fix proposal for JDK-8211698.

http://cr.openjdk.java.net/~rraghavan/8211698/webrev.00/
https://bugs.openjdk.java.net/browse/JDK-8211698

Please note the main fix added is to correctly register the new 
Opaque4Node generated in PhaseIdealLoop::add_range_check_predicate 
[loopTransform.cpp].
Also included other minor changes overlooked during old related 
JDK-8193130 fix.
Thanks to Tobias Hartmann and Roland Westrelin for all help with 
analysis, identifying the fix.

No issues with testing - hs-tier1 - 4, hs-precheckin-comp

Thanks,
Rahul