RFR: 8313612: Use JUnit in lib-test/jdk tests [v2]

[Qing Xiao]

> Modified all tests under lib-test/jdk to use JUnit

Qing Xiao has updated the pull request incrementally with three additional commits since the last revision:

 - Delete extra space
   
   Co-authored-by: Andrey Turbanov <turbanoff at gmail.com>
 - Update years in comments in test/lib-test/jdk/test/lib/hexdump
   
   Co-authored-by: Christian Stein <sormuras at gmail.com>
 - Update years in comments in test/lib-test/jdk/test/lib/hexdump
   
   Co-authored-by: Christian Stein <sormuras at gmail.com>

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/15131/files
  - new: https://git.openjdk.org/jdk/pull/15131/files/1ab34e8d..0e15e752

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15131&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15131&range=00-01

  Stats: 3 lines in 2 files changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/15131.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15131/head:pull/15131

PR: https://git.openjdk.org/jdk/pull/15131