RFR: 8259512: Update --release 16 symbol information for JDK 16 build 31

[Joe Darcy]

Using the symbol updating script, update the symbol files for API changes in JDK 16 build 31.

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Commit messages:
 - 8259512: Update --release 16 symbol information for JDK 16 build 31

Changes: https://git.openjdk.java.net/jdk/pull/2010/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2010&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8259512
  Stats: 9 lines in 1 file changed: 8 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2010.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2010/head:pull/2010

PR: https://git.openjdk.java.net/jdk/pull/2010