An oversight in the patch for [JDK-8338544](https://bugs.openjdk.org/browse/JDK-8338544) #20665 caused `ClassDesc` to incorrectly accept empty strings as binary names. This patch fixes that problem, and unifies the checks for package and class nominal descriptors.
------------- Commit messages: - 8343437: ClassDesc.of incorrectly permitting empty names Changes: https://git.openjdk.org/jdk/pull/21830/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21830&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8343437 Stats: 48 lines in 5 files changed: 22 ins; 6 del; 20 mod Patch: https://git.openjdk.org/jdk/pull/21830.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/21830/head:pull/21830 PR: https://git.openjdk.org/jdk/pull/21830
