[jdk17u-dev] RFR: 8273162: AbstractSplittableWithBrineGenerator does not create a random salt

[Aleksey Shipilev]

Transplanted from https://github.com/openjdk/jdk17u/pull/288.

Additional testing:
 - `java/util/Random` tests

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Commit messages:
 - Backport 5e1df2c7d71e9393beaa4fd2d8812b065d053392

Changes: https://git.openjdk.java.net/jdk17u-dev/pull/6/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u-dev&pr=6&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8273162
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk17u-dev/pull/6.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u-dev pull/6/head:pull/6

PR: https://git.openjdk.java.net/jdk17u-dev/pull/6