RFR: 8314320: Mark runtime/CommandLine/ tests as flagless

[Leonid Mesnik]

The tests in runtime/CommandLine test command-line options and ignore external VM flags.
No need to run them with any additional GC/Compiler flags etc.

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Commit messages:
 - fixed headers

Changes: https://git.openjdk.org/jdk/pull/15299/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15299&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8314320
  Stats: 56 lines in 23 files changed: 31 ins; 1 del; 24 mod
  Patch: https://git.openjdk.org/jdk/pull/15299.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15299/head:pull/15299

PR: https://git.openjdk.org/jdk/pull/15299