RFR: 8346552: C2: Add IR tests to check that Parse Predicate cloning in Loop Unswitching works as expected [v3]

[Manuel Hässig]

> # Issue Summary
> 
> When a loop is unswitched, all parse predicates from the original loop must be cloned to the second loop that is created. Forgetting to clone a parse predicate is a common error during development on loop unswitching code that we could not catch previously. Since we have the IR-framework now, this PR introduces a test to catch this error.
> 
> # Changes
> 
> The main contribution of this PR is a test to ensure that all predicates have been cloned into an unswitched loop. This also required some relating changes:
>  - add `OPAQUE_TEMPLATE_ASSERTION_PREDICATE_NODE` to the IR-framework,
>  - add some missing parse predicate nodes to the IR-framework,
>  - change the output of the labels of parse predicate nodes in the ideal graph so they can be recognized reliably by the IR-framework (the main problem was that `Loop ` is a prefix of `Loop Limit Check` that is hard to distinguish with spaces instead of underlines),
>  - rework the regex for detecting parse predicates in the IR-framework,
>  - add a test to ensure parse predicates are cloned into unswitched loops.
> 
> # Testing
> 
> - [Github Actions](https://github.com/mhaessig/jdk/actions/runs/14266369099)
> - tier1 through tier3 plus Oracle internal testing

Manuel Hässig has updated the pull request incrementally with two additional commits since the last revision:

 - Add suggested comment
   
   Co-authored-by: Christian Hagedorn <christian.hagedorn at oracle.com>
 - Remove -Xcomp and replace with Warmup(0)

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/24479/files
  - new: https://git.openjdk.org/jdk/pull/24479/files/fc3d5d11..0a4d89ff

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24479&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24479&range=01-02

  Stats: 6 lines in 1 file changed: 2 ins; 1 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/24479.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24479/head:pull/24479

PR: https://git.openjdk.org/jdk/pull/24479