Add missing core Object methods. (#792)

Author: CedNaru

kt/godot-library/godot-core-library/src/main/kotlin/godot/core/KtObject.kt

@@ -55,6 +55,15 @@ abstract class KtObject : NativeWrapper {
 
     protected abstract fun new(scriptIndex: Int)
 
+    open fun _get(property: StringName): Any = throw NotImplementedError("_get is not implemented for Object")
+    open fun _getPropertyList(): VariantArray<Dictionary<Any, Any>> = throw NotImplementedError("_getPropertyList is not implemented for Object")
+    open fun _propertyCanRevert(name: StringName) : Boolean = throw NotImplementedError("_propertyCanRevert is not implemented for Object")
+    open fun _propertyGetRevert(name: StringName): Any = throw NotImplementedError("_propertyGetRevert is not implemented for Object")
+    open fun _set(name: StringName, value: Any) : Unit = throw NotImplementedError("_set is not implemented for Object")
+    open fun _toString(): String = throw NotImplementedError("_toString is not implemented for Object")
+    open fun _validateProperty(): Boolean = throw NotImplementedError("_validateProperty is not implemented for Object")
+
+
     open fun _notification(): GodotNotification = godotNotification {}
 
     @Suppress("UNCHECKED_CAST")
@@ -78,7 +87,7 @@ abstract class KtObject : NativeWrapper {
 
 
     private fun removeScript(constructorIndex: Int) {
-        createScriptInstance(ptr, objectID,  TypeManager.engineTypesConstructors[constructorIndex])
+        createScriptInstance(ptr, objectID, TypeManager.engineTypesConstructors[constructorIndex])
     }
 
     protected external fun createNativeObject(classIndex: Int, scriptIndex: Int)

src/script/jvm_instance.cpp

@@ -164,7 +164,17 @@ void JvmInstance::validate_property(PropertyInfo& p_property) const {
 }
 
 String JvmInstance::to_string(bool* r_valid) {
-    return ScriptInstance::to_string(r_valid);
+    jni::Env env {jni::Jvm::current_env()};
+
+    if (KtFunction* function {kt_class->get_method(SNAME("_to_string"))}) {
+        const int arg_count = 0;
+        Variant ret;
+        function->invoke(env, kt_object, nullptr, arg_count, ret);
+        *r_valid = true;
+        return ret.operator String();
+    }
+    *r_valid = false;
+    return {};
 }
 
 void JvmInstance::refcount_incremented() {