[jdk21u-dev] RFR: 8334016: Make PrintNullString.java automatic

[Goetz Lindenmaier]

I backport this for parity with 21.0.9-oracle

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Commit messages:
 - Backport f5e6d2c93c3274e465c42709b7634463899fdf2e

Changes: https://git.openjdk.org/jdk21u-dev/pull/2042/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=2042&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8334016
  Stats: 163 lines in 1 file changed: 37 ins; 88 del; 38 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/2042.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/2042/head:pull/2042

PR: https://git.openjdk.org/jdk21u-dev/pull/2042