RFR: 8364970: Redo JDK-8327381 by updating the CmpU type instead of the Bool type [v4]

[Francisco Ferrari Bihurriet]

> Hi, this pull request is a second take of 1383fec41756322bf2832c55633e46395b937b40, by updating the `CmpUNode` type as either `TypeInt::CC_LE` (case 1a) or `TypeInt::CC_LT` (case 1b) instead of updating the `BoolNode` type as `TypeInt::ONE`.
> 
> With this approach a56cd371a2c497e4323756f8b8a08a0bba059bf2 becomes unnecessary. Additionally, having the right type in `CmpUNode` could potentially enable further optimizations.
> 
> #### Testing
> 
> In order to evaluate the changes, the following testing has been performed:
> 
> * `jdk:tier1` (see [GitHub Actions run](https://github.com/franferrax/jdk/actions/runs/16789994433))
> * [`TestBoolNodeGVN.java`](https://github.com/openjdk/jdk/blob/jdk-26+9/test/hotspot/jtreg/compiler/c2/gvn/TestBoolNodeGVN.java), created for [JDK-8327381: Refactor type-improving transformations in BoolNode::Ideal to BoolNode::Value](https://bugs.openjdk.org/browse/JDK-8327381) (1383fec41756322bf2832c55633e46395b937b40)
>     * I also checked it breaks if I remove the `CmpUNode::Value_cmpu_and_mask` call
> * Private reproducer for [JDK-8349584: Improve compiler processing](https://bugs.openjdk.org/browse/JDK-8349584) (a56cd371a2c497e4323756f8b8a08a0bba059bf2)
> * A local slowdebug run of the `test/hotspot/jtreg/compiler/c2` category on _Fedora Linux x86_64_
>     * Same results as with `master` (f95af744b07a9ec87e2507b3d584cbcddc827bbd)

Francisco Ferrari Bihurriet has updated the pull request incrementally with one additional commit since the last revision:

  Make testCorrectness @Run the C2 compiled versions
  
  Correctness of the tests with the following name format should be
  checked in the TestFramework.run() JVM process, with the C2 compiled
  version of these methods. TestFramework's warmup ensures this.
  
  testCase(1a|1b)(OptimizeAsTrue|OptimizeAsFalse)For(EQ|NE|LE|GE|LT|GT)(xm|mx)

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/26666/files
  - new: https://git.openjdk.org/jdk/pull/26666/files/e6b1cb89..e2f8a43c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26666&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26666&range=02-03

  Stats: 33 lines in 1 file changed: 16 ins; 17 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/26666.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26666/head:pull/26666

PR: https://git.openjdk.org/jdk/pull/26666