ART: More refactor for JVMTI run tests (1/3)

Put (most) tests into a new package and give them dedicated
class names (Test9XY).

NOTE: BROKEN WITHOUT A FOLLOW-UP CL TO CHANGE DIRECTORY STRUCTURE
      AND FILE NAMES!

Bug: 32072923
Test: None
Change-Id: I291b0543f7782914e446a74f0d9037020c88e5b5
diff --git a/test/911-get-stack-trace/src/OtherThread.java b/test/911-get-stack-trace/src/OtherThread.java
index 0a78523..675bff5 100644
--- a/test/911-get-stack-trace/src/OtherThread.java
+++ b/test/911-get-stack-trace/src/OtherThread.java
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+package art;
+
 public class OtherThread {
   public static void doTestOtherThreadWait() throws Exception {
     System.out.println("################################");