RFR: 8311248: Refactor CodeCache::initialize_heaps to simplify adding new CodeCache segments [v12]

[Boris Ulasevich]

> These changes clean up the logic and the code of allocating codecache segments and add more testing of it, to open a door for further optimization of code cache segmentation.  The goal was to keep the behavior as close to the existing behavior as possible, even if it's not quite logical.
> 
> Also, these changes better account for alignment - PrintFlagsFinal shows the final aligned segment sizes, and the segments fill the ReservedCodeCacheSize without gaps caused by alignment.

Boris Ulasevich has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains one commit:

  8311248: Refactor CodeCache::initialize_heaps to simplify adding new CodeCache segments

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Changes: https://git.openjdk.org/jdk/pull/17244/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17244&range=11
  Stats: 325 lines in 5 files changed: 175 ins; 99 del; 51 mod
  Patch: https://git.openjdk.org/jdk/pull/17244.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17244/head:pull/17244

PR: https://git.openjdk.org/jdk/pull/17244