RFR: 8328528: C2 should optimize long-typed parallel iv in an int counted loop [v9]

[Kangcheng Xu]

> Currently, parallel iv optimization only happens in an int counted loop with int-typed parallel iv's. This PR adds support for long-typed iv to be optimized. 
> 
> Additionally, this ticket contributes to the resolution of [JDK-8275913](https://bugs.openjdk.org/browse/JDK-8275913). Meanwhile, I'm working on adding support for parallel IV replacement for long counted loops which will depend on this PR.

Kangcheng Xu has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 27 additional commits since the last revision:

 - Merge branch 'master' into long-typed-parallel-iv
 - use @run driver and Argument.RANDOM_ONCE
 - Merge branch 'master' into long-typed-parallel-iv
 - add random strides to tests
 - fix tests on larger strides
 - add more expressive comments and test cases
 - Merge branch 'master' into long-typed-parallel-iv
 - update comments to clarify on type casting
 - add pseudocode for subgraphs before/after the transformation
 - remove WIP support for long counted loops
 - ... and 17 more: https://git.openjdk.org/jdk/compare/93db32b9...20bdc791

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/18489/files
  - new: https://git.openjdk.org/jdk/pull/18489/files/596dbf9a..20bdc791

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18489&range=08
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18489&range=07-08

  Stats: 60236 lines in 1886 files changed: 34337 ins; 16939 del; 8960 mod
  Patch: https://git.openjdk.org/jdk/pull/18489.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18489/head:pull/18489

PR: https://git.openjdk.org/jdk/pull/18489