Implement getting of 64-bit locals (double, long).

Also implement the JDWP "GetClassLoader" request, used by jswat's "classes"
command.

Also implement the JDWP "exit" request, tested with jswat's "shutdown".

Change-Id: Ic8424a332151242211d8a772721deb3199b24682
diff --git a/src/dalvik_system_VMStack.cc b/src/dalvik_system_VMStack.cc
index d87bc2b..682aed9 100644
--- a/src/dalvik_system_VMStack.cc
+++ b/src/dalvik_system_VMStack.cc
@@ -59,7 +59,7 @@
   // TODO: need SmartFrame (Thread::WalkStack-like iterator).
   for (Frame frame = self->GetTopOfStack(); frame.HasNext(); frame.Next()) {
     Class* c = frame.GetMethod()->GetDeclaringClass();
-    Object* cl = const_cast<ClassLoader*>(c->GetClassLoader());
+    Object* cl = c->GetClassLoader();
     if (cl != bootstrap && cl != system) {
       return AddLocalReference<jobject>(env, cl);
     }