RFR: 8356995: Provide default methods min(T, T) and max(T, T) in Comparator interface [v4]

[Tagir F. Valeev]

> Implementation of Comparator.min and Comparator.max methods. Preliminary discussion is in this thread:
> https://mail.openjdk.org/pipermail/core-libs-dev/2025-May/145638.html
> The specification is mostly composed of Math.min/max and Collections.min/max specifications. 
> 
> The methods are quite trivial, so I don't think we need more extensive testing (e.g., using different comparators). But if you have ideas of new useful tests, I'll gladly add them.
> 
> I'm not sure whether we should specify exactly the behavior in case if the comparator returns 0. I feel that it could be a useful invariant that `Comparator.min(a, b)` and `Comparator.max(a, b)` always return different argument, partitioning the set of {a, b} objects (even if they are equal). But I'm open to suggestions here.

Tagir F. Valeev has updated the pull request incrementally with one additional commit since the last revision:

  Make min and max generic

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/25297/files
  - new: https://git.openjdk.org/jdk/pull/25297/files/b750c3fa..38f9eb71

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25297&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25297&range=02-03

  Stats: 15 lines in 2 files changed: 13 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/25297.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25297/head:pull/25297

PR: https://git.openjdk.org/jdk/pull/25297