RFR: 8344171: Clone and initialize Assertion Predicates in order instead of in reverse-order [v3]

[Christian Hagedorn]

> (Note: This is a dependent PR on https://github.com/openjdk/jdk/pull/22136 which is not fully reviewed, yet, but I'd like to already send this PR out for review since I'm away for the rest of the week)
> 
> This patch changes the order in which we clone and initialize Assertion Predicates from "reverse-order" to "in-order".
> 
> #### Current State: Mostly "reverse-order" for Assertion Predicates
> We are currently cloning and initializing Assertion Predicates in reverse-order out of convenience and simplicity for most of the loop splitting optimizations - except for Loop Unswitching (see next section). This means that we do the following:
> 
>                                      old target loop entry
>                                                |
>          x                         Cloned Template Assertion
>          |                                Predicate 2
> Template Assertion                             |
>     Predicate 1                       Initialized Assertion
>          |               ==>               Predicate 2
> Template Assertion                             |
>     Predicate 2                    Cloned Template Assertion
>          |                                Predicate 1
>     source loop                                |
>                                       Initialized Assertion
>                                            Predicate 1
>                                                |
>                                           target loop
> 
> I don't think this is wrong but still kinda unexpected when trying to reason about a graph. But now with the recent refactorings, I think it's easy to change this to an in-order processing:
> 
>                                      old target loop entry
>                                                |
>          x                          Cloned Template Assertion
>          |                                Predicate 1
> Template Assertion                             |
>     Predicate 1                       Initialized Assertion
>          |               ==>               Predicate 1
> Template Assertion                             |
>     Predicate 2                     Cloned Template Assertion
>          |                                Predicate 2
>     source loop                                |
>                                       Initialized Assertion
>                                            Predicate 2
>                                                |
>                                           target loop
> 
>  This will also align all cloni...

Christian Hagedorn has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains five commits:

 - Merge branch 'master' of https://git.openjdk.org/jdk into JDK-8344171
 - Update comment
 - 8344171: Clone and initialize Assertion Predicates in order instead of in reverse-order
 - Apply suggestions from code review
   
   Co-authored-by: Tobias Hartmann <tobias.hartmann at oracle.com>
 - 8344213: Cleanup OpaqueLoop*Node verification code for Assertion Predicates

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

Changes: https://git.openjdk.org/jdk/pull/22275/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22275&range=02
  Stats: 87 lines in 4 files changed: 41 ins; 33 del; 13 mod
  Patch: https://git.openjdk.org/jdk/pull/22275.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22275/head:pull/22275

PR: https://git.openjdk.org/jdk/pull/22275