Implement ThreadReference.CurrentContendedMonitor and ThreadReference.Interrupt.

The JDWP test for CurrentContendedMonitor also uses Interrupt.

Change-Id: Id1f6add29b578a0494da672d21dd54f23e866475
diff --git a/src/debugger.h b/src/debugger.h
index c58fd4f..b033ace 100644
--- a/src/debugger.h
+++ b/src/debugger.h
@@ -155,6 +155,8 @@
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
   static JDWP::JdwpError GetOwnedMonitors(JDWP::ObjectId thread_id, std::vector<JDWP::ObjectId>& monitors)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  static JDWP::JdwpError GetContendedMonitor(JDWP::ObjectId thread_id, JDWP::ObjectId& contended_monitor)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   static JDWP::JdwpError GetArrayLength(JDWP::ObjectId array_id, int& length)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
@@ -275,6 +277,8 @@
                             JDWP::JdwpTag tag, uint64_t value, size_t width)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
+  static JDWP::JdwpError Interrupt(JDWP::ObjectId thread_id);
+
   /*
    * Debugger notification
    */