ART: Rewrite test 911

Use explicit thread names to avoid output reliance on implicit
thread naming.

Bug: 31684812
Test: m test-art-host-run-test-911-get-stack-trace
Change-Id: I82004fea6f49831b5d378bef2c290b61c694a07a
diff --git a/test/911-get-stack-trace/src/OtherThread.java b/test/911-get-stack-trace/src/OtherThread.java
index 0748433..0a78523 100644
--- a/test/911-get-stack-trace/src/OtherThread.java
+++ b/test/911-get-stack-trace/src/OtherThread.java
@@ -21,7 +21,7 @@
     System.out.println("################################");
     final ControlData data = new ControlData();
     data.waitFor = new Object();
-    Thread t = new Thread() {
+    Thread t = new Thread("OtherThread doTestOtherThreadWait") {
       public void run() {
         Recurse.foo(4, 0, 0, data);
       }
@@ -54,7 +54,7 @@
     System.out.println("### Other thread (live) ###");
     System.out.println("###########################");
     final ControlData data = new ControlData();
-    Thread t = new Thread() {
+    Thread t = new Thread("OtherThread doTestOtherThreadBusyLoop") {
       public void run() {
         Recurse.foo(4, 0, 0, data);
       }