If a module was added after JDK 9 and did not have a preview stage `SinceChecker` identifies the "real" since-version of the module as 9.

For example, the following tests all fail with errors like "module: <module name>: `@since` version is <version> but the element exists before JDK 10":
```
/*
 * @test
 * @library /test/lib /test/jdk/tools/sincechecker
 * @run main SinceChecker jdk.internal.md
 */

/*
 * @test
 * @library /test/lib /test/jdk/tools/sincechecker
 * @run main SinceChecker jdk.graal.compiler
 */

/*
 * @test
 * @library /test/lib /test/jdk/tools/sincechecker
 * @run main SinceChecker jdk.graal.compiler.management
 */
```