Dump the native stacks of threads in VmWait as well Native.

Mostly these are boring, but when they're boring they're also short.
And sometimes they're interesting.

Bug: 6294717

Change-Id: I1bf9e32a5cc237efda365abe39ad84ac59fd5c8f
diff --git a/vm/Thread.cpp b/vm/Thread.cpp
index 1ced9ca..01451f3 100644
--- a/vm/Thread.cpp
+++ b/vm/Thread.cpp
@@ -3345,7 +3345,7 @@
     dumpSchedStat(target, thread->systemTid);
 
     /* grab the native stack, if possible */
-    if (thread->status == THREAD_NATIVE) {
+    if (thread->status == THREAD_NATIVE || thread->status == THREAD_VMWAIT) {
         dvmDumpNativeStack(target, thread->systemTid);
     }