JEP 493 added a feature to link runtimes without JMOD files.

When enabling that feature (e.g. through configure option --enable-linkable-runtime) and also using the option to ship external symbols of type "public" on Windows (--with-external-symbols-in-bundles=public), e.g. stripped pdb files that don't contain full debug information but help to get line numbers in hs_err files, several tests related to JLink fail.

For instance the test "tools/jlink/basic/BasicTest.java" fails and you find error output like this:
Error: <test-vm-path>\\bin\\keytool.exe.pdb has been modified