RFR: 8302815 Use new Math.clamp method in core libraries [v3]

[Tagir F. Valeev]

> For cleanup and dogfooding the new method, it would be nice to use Math.clamp where possible in java.base. See PR #12428.
> 
> As Math.clamp performs an additional check that min is not greater than max, I conservatively replaced only those occurrences where I can see that this invariant is always held. There are more occurrences, where clamp can be potentially used but it's unclear whether min <= max is always true.

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

  Update copyright year

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Changes:
  - all: https://git.openjdk.org/jdk/pull/12633/files
  - new: https://git.openjdk.org/jdk/pull/12633/files/be13683b..e3fb1502

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12633&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12633&range=01-02

  Stats: 8 lines in 8 files changed: 0 ins; 0 del; 8 mod
  Patch: https://git.openjdk.org/jdk/pull/12633.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12633/head:pull/12633

PR: https://git.openjdk.org/jdk/pull/12633