Please review a simple fix to prevent `java.lang.AssertionError` to be thrown when the `javadoc` `-subpackages` option is used with a `-source` release that doesn't support modules.
------------- Commit messages: - JDK-8325090: javadoc fails when -subpackages option is used with non-modular -source Changes: https://git.openjdk.org/jdk/pull/21201/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21201&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8325090 Stats: 82 lines in 2 files changed: 77 ins; 0 del; 5 mod Patch: https://git.openjdk.org/jdk/pull/21201.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/21201/head:pull/21201 PR: https://git.openjdk.org/jdk/pull/21201
