Stash the directly-implemented interfaces in Proxy so we can implement Class.getInterfaces.

Also extend test 044 to spot this (found by a libcore test).

Change-Id: I50019db49c549f045d94173c3ed9ae81f05ef858
diff --git a/src/object.h b/src/object.h
index 93493fd..fee4dd0 100644
--- a/src/object.h
+++ b/src/object.h
@@ -2508,10 +2508,16 @@
 
 class MANAGED SynthesizedProxyClass : public Class {
  public:
+  ObjectArray<Class>* GetInterfaces() {
+    return interfaces_;
+  }
+
   ObjectArray<ObjectArray<Class> >* GetThrows() {
     return throws_;
   }
+
  private:
+  ObjectArray<Class>* interfaces_;
   ObjectArray<ObjectArray<Class> >* throws_;
   DISALLOW_IMPLICIT_CONSTRUCTORS(SynthesizedProxyClass);
 };