RFR: 8265132 : C2 compilation fails with assert "missing precedence edge" [v5]

[Jamsheed Mohammed C M]

> Issue is similar to https://bugs.openjdk.java.net/browse/JDK-8261730
> but happens at next https://github.com/jamsheedcm/jdk/blob/master/src/hotspot/share/opto/gcm.cpp#L830
> 
> Request for review

Jamsheed Mohammed C M has updated the pull request incrementally with one additional commit since the last revision:

  review feedback by VladimirK, Version02 improved

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/4200/files
  - new: https://git.openjdk.java.net/jdk/pull/4200/files/080d2270..1d41d5ca

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=4200&range=04
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=4200&range=03-04

  Stats: 41 lines in 2 files changed: 4 ins; 27 del; 10 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4200.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4200/head:pull/4200

PR: https://git.openjdk.java.net/jdk/pull/4200