RFR: 8349848: Support lint control of sunapi diagnostics

[Archie Cobbs]

This PR creates a new lint category `proprietary` that controls the mandatory warning "Foo is internal proprietary API and may be removed in a future release".

This allows developers to suppress this warning using `-Xlint:-proprietary` and/or `@SuppressWarnings`.

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Commit messages:
 - Add "proprietary" lint category for internal proprietary API warnings.

Changes: https://git.openjdk.org/jdk/pull/23650/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23650&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8349848
  Stats: 202 lines in 15 files changed: 190 ins; 2 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/23650.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23650/head:pull/23650

PR: https://git.openjdk.org/jdk/pull/23650