[jdk21u-dev] RFR: 8321164: javac with annotation processor throws AssertionError: Filling jrt:/... during JarFileObject[/...]

[Aleksey Shipilev]

Clean backport to fix a corner case in javac.

Additional testing:
 - [x] macos-aarch64-server-fastdebug, new regression test fails without the patch, passes with it
 - [x] macos-aarch64-server-fastdebug, `langtools_all` pass

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Commit messages:
 - Backport 03c4595173d564df97aa4f2b3156adcd4be379fa

Changes: https://git.openjdk.org/jdk21u-dev/pull/146/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=146&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8321164
  Stats: 134 lines in 2 files changed: 124 ins; 0 del; 10 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/146.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/146/head:pull/146

PR: https://git.openjdk.org/jdk21u-dev/pull/146