RFR: 8297343: TestStress*.java fail with "got different traces for the same seed" [v3]

[Roland Westrelin]

> Root cause from Roberto's analysis:
> 
> "The regression seems to be due to the introduction of non-determinism
> in the node dumps of otherwise identical compilations."
> 
> "The problem seems to be that JDK-6312651 dumps interface sets in an
> order that is determined by the raw pointers of the set elements. This
> is unstable across different runs and leads to different node dumps
> for otherwise identical compilations."
> 
> "Stable node dumps are useful for debugging (e.g. when diffing
> compiler traces from two different runs), so the solution is probably
> dumping interface sets in some order (e.g. lexicographic order of each
> interface dump) that does not depend on raw pointer values."
> 
> This patch implements Roberto's recommendation by sorting interfaces
> on their ciBaseObject::_ident.

Roland Westrelin has updated the pull request incrementally with one additional commit since the last revision:

  Revert "8297347: Problem list compiler/debug/TestStress*.java"
  
  This reverts commit 0b04a99245795c223a01d1cbe66a46d20e480c53.

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/11357/files
  - new: https://git.openjdk.org/jdk/pull/11357/files/a4aea940..1a9fbf3a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11357&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11357&range=01-02

  Stats: 3 lines in 1 file changed: 0 ins; 3 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/11357.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11357/head:pull/11357

PR: https://git.openjdk.org/jdk/pull/11357