Clean up creating handles from `this`.

Make these member functions static and take an additional
parameter `Handle<.> h_this`. Callers mostly already have
a Handle<> to pass, so we avoid an extra StackHandleScope.
This pattern was already used for some functions.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing --interpreter
Change-Id: I4f4478b0526bcb2f3c23305d3b3cc4a65fff9ff5
diff --git a/runtime/native/java_lang_Class.cc b/runtime/native/java_lang_Class.cc
index f69d1bc..4967f9e 100644
--- a/runtime/native/java_lang_Class.cc
+++ b/runtime/native/java_lang_Class.cc
@@ -220,7 +220,11 @@
   Handle<mirror::Class> klass = hs.NewHandle(DecodeClass(soa, javaThis));
 
   if (klass->IsProxyClass()) {
-    return soa.AddLocalReference<jobjectArray>(klass->GetProxyInterfaces()->Clone(soa.Self()));
+    StackHandleScope<1> hs2(soa.Self());
+    Handle<mirror::ObjectArray<mirror::Class>> interfaces =
+        hs2.NewHandle(klass->GetProxyInterfaces());
+    return soa.AddLocalReference<jobjectArray>(
+        mirror::ObjectArray<mirror::Class>::Clone(interfaces, soa.Self()));
   }
 
   const dex::TypeList* iface_list = klass->GetInterfaceTypeList();