RFR: JDK-8325148: Enable restricted javac warning in java.base

[Joe Darcy]

The restricted javac warning is disabled for java.base, but could be enabled by suppressing the warning in a handful of files.

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Commit messages:
 - JDK-8325148: Enable restricted javac warning in java.base

Changes: https://git.openjdk.org/jdk/pull/17677/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17677&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8325148
  Stats: 26 lines in 9 files changed: 10 ins; 0 del; 16 mod
  Patch: https://git.openjdk.org/jdk/pull/17677.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17677/head:pull/17677

PR: https://git.openjdk.org/jdk/pull/17677