RFR: 8320192: SHAKE256 does not work correctly if n >= 137

[Weijun Wang]

When blocksize is less than digest output length, call `keccak` more.

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Commit messages:
 - initial change

Changes: https://git.openjdk.org/jdk/pull/16698/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=16698&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8320192
  Stats: 159 lines in 4 files changed: 148 ins; 1 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/16698.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16698/head:pull/16698

PR: https://git.openjdk.org/jdk/pull/16698