LibJS: Add JSON.parse

Author: https://github.com/mattco98
Commit: b155e64b67
Pull-request: https://github.com/SerenityOS/serenity/pull/2545
Reviewed-by: https://github.com/Dexesttp
Reviewed-by: https://github.com/awesomekling

Libraries/LibJS/Runtime/JSONObject.h

@@ -26,8 +26,6 @@
 
 #pragma once
 
-#include <LibJS/Runtime/Object.h>
-
 namespace JS {
 
 class JSONObject final : public Object {
@@ -52,6 +50,12 @@ private:
     static String serialize_json_array(Interpreter&, StringifyState&, Object&);
     static String quote_json_string(String);
 
+    // Parse helpers
+    static Object* parse_json_object(Interpreter&, const JsonObject&);
+    static Array* parse_json_array(Interpreter&, const JsonArray&);
+    static Value parse_json_value(Interpreter&, const JsonValue&);
+    static Value internalize_json_property(Interpreter&, Object* holder, const PropertyName& name, Function& reviver);
+
     static Value stringify(Interpreter&);
     static Value parse(Interpreter&);
 };