RFR: 8341977: Replace predicate walking and cloning code for Loop Peeling with a predicate visitor [v3]

[Christian Hagedorn]

> #### Replacing the Remaining Predicate Walking and Cloning Code 
> In the next series of patches (this, [JDK-8342943](https://bugs.openjdk.org/browse/JDK-8342943), [JDK-8342945](https://bugs.openjdk.org/browse/JDK-8342945), and [JDK-8342946](https://bugs.openjdk.org/browse/JDK-8342946)) I want to replace the predicate walking and cloning code used for Loop Peeling, Pre/Main/Post Loops, Loop Unswitching, removing useless Assertion Predicates and Loop Unrolling with new `PredicateVisitors` which can be used in combination with the new `PredicateIterator`.
> 
> #### Single Template Assertion Predicate Check
> This replacement allows us to have a single `TemplateAssertionPredicate::is_predicate()` check that is called for all predicate matching code. This enables the removal of uncommon traps for Template Assertion Predicates with [JDK-8342047](https://bugs.openjdk.org/browse/JDK-8342047) which is a missing piece in order to fix the remaining problems with Assertion Predicates ([JDK-8288981](https://bugs.openjdk.org/browse/JDK-8288981)).
> 
> #### Common Refactorings for all the Patches in this Series
> In each of the patch, I will do similar refactoring ideas:
> - Replace the existing code in the corresponding `PhaseIdealLoop` method with call to a new (or existing) predicate visitor which extends the `PredicateVisitor` interface. 
> - The visitor implements the Assertion Predicate `visit()` methods to implement the cloning and initialization of the Template Assertion Predicates.
> - The predicate visitor is then passed to the `PredicateIterator` which walks through all predicates found at a loop and applies the visitor for each predicate. 
> - The visitor creates new nodes (if there are Template Assertion Predicates) either in place or at the loop entry of a target loop. In the latter case, the calling code of the `PredicateIterator` must make sure to connect the tail of the newly created predicate chain after the old loop entry to the target loop head (see **P1** PR comment).
> - Keep the semantics which includes to only apply the Template Assertion Predicate processing if there are Parse Predicates (see **P2** PR comment). This limitation should eventually be removed. But I want to do that separately at a later point.
> 
> #### Refactorings of this Patch
> This first patch replaces the predicate walking and cloning code for Loop Peeling and lays the foundation for the replacement for main/post loops ([JDK-8342943](https://bugs.openjdk.org/browse/JDK-8342943)) which is quite similar. Th...

Christian Hagedorn has updated the pull request incrementally with one additional commit since the last revision:

  Review Emanuel

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Changes:
  - all: https://git.openjdk.org/jdk/pull/21679/files
  - new: https://git.openjdk.org/jdk/pull/21679/files/eb22d38e..79a59130

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21679&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21679&range=01-02

  Stats: 19 lines in 3 files changed: 1 ins; 0 del; 18 mod
  Patch: https://git.openjdk.org/jdk/pull/21679.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21679/head:pull/21679

PR: https://git.openjdk.org/jdk/pull/21679