RFR: 8267861: Update SourceVersion with new language features in 16 and 17

[Joe Darcy]

Update SourceVersion constants for 16 and 17 with language features for those releases.

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Commit messages:
 - 8267861: Update SourceVersion with new language features in 16 and 17

Changes: https://git.openjdk.java.net/jdk/pull/4294/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4294&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8267861
  Stats: 6 lines in 1 file changed: 6 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4294.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4294/head:pull/4294

PR: https://git.openjdk.java.net/jdk/pull/4294