IDL: Add build target for IDL dictionary impl generation in core

Source/bindings/tests/results/V8TestObject.cpp

Index: Source/bindings/tests/results/V8TestObject.cpp
diff --git a/Source/bindings/tests/results/V8TestObject.cpp b/Source/bindings/tests/results/V8TestObject.cpp
index 7812d7d905d45e819262462c69b4f79d60903fb3..2343c5237f0e0e89dfce63dea4dd5b883428dfac 100644
--- a/Source/bindings/tests/results/V8TestObject.cpp
+++ b/Source/bindings/tests/results/V8TestObject.cpp
@@ -8190,7 +8190,11 @@ static void overloadedMethodJ2Method(const v8::FunctionCallbackInfo<v8::Value>&
     {
         v8::TryCatch block;
         V8RethrowTryCatchScope rethrow(block);
-        TONATIVE_VOID_INTERNAL(testDictionaryArg, V8TestDictionary::toNative(info.GetIsolate(), info[0]));
+        if (!info[0]->IsUndefined()) {
+            TONATIVE_VOID_INTERNAL(testDictionaryArg, V8TestDictionary::toNative(info.GetIsolate(), info[0]));
+        } else {
+            testDictionaryArg = TestDictionary::create();
+        }
     }
     impl->overloadedMethodJ(testDictionaryArg);
 }