RFR: 8332675: test/hotspot/jtreg/gc/testlibrary/Helpers.java compileClass javadoc does not match after 8321812

[Matthias Baesken]

The javadoc for compileClass needs updating after JDK-8321812 .

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

Commit messages:
 - JDK-8332675

Changes: https://git.openjdk.org/jdk/pull/19348/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19348&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8332675
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/19348.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19348/head:pull/19348

PR: https://git.openjdk.org/jdk/pull/19348