https://github.com/openjdk/jdk/blob/699a3cde74eac74fb54b2ade94d437c010449f89/src/hotspot/share/oops/instanceKlass.cpp#L2928

There's no checks of "the package of the InstanceKlass is in the boot loader's package entry table" in the product build.

// Function set_classpath_index checks if the package of the InstanceKlass is in the
// boot loader's package entry table. If so, then it sets the classpath_index
// in the package entry record.
//
// The classpath_index field is used to find the entry on the boot loader class
// path for packages with classes loaded by the boot loader from -Xbootclasspath/a
// in an unnamed module. It is also used to indicate (for all packages whose
// classes are loaded by the boot loader) that at least one of the package's
// classes has been loaded.
void InstanceKlass::set_classpath_index(s2 path_index, TRAPS) {
  if (_package_entry != NULL) {
    DEBUG_ONLY(PackageEntryTable* pkg_entry_tbl = ClassLoaderData::the_null_class_loader_data()->packages();)
    assert(pkg_entry_tbl->lookup_only(_package_entry->name()) == _package_entry, "Should be same");
    assert(path_index != -1, "Unexpected classpath_index");
    _package_entry->set_classpath_index(path_index);
  }
}