[jdk25u-dev] RFR: 8364248: Separate commit and reservation limit detection

[Aleksey Shipilev]

This cleanup makes further backports in container code cleaner. Notably, it is on the way to [JDK-8370572](https://bugs.openjdk.org/browse/JDK-8370572) backport.

Additional testing:
 - [x] Linux x86_64 server fastdebug, `hotspot_gc`

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

Commit messages:
 - Backport ae11d8f44689502d35cb511e9ce288ab7cc0acae

Changes: https://git.openjdk.org/jdk25u-dev/pull/11/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk25u-dev&pr=11&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8364248
  Stats: 107 lines in 5 files changed: 45 ins; 38 del; 24 mod
  Patch: https://git.openjdk.org/jdk25u-dev/pull/11.diff
  Fetch: git fetch https://git.openjdk.org/jdk25u-dev.git pull/11/head:pull/11

PR: https://git.openjdk.org/jdk25u-dev/pull/11