fix: resolve function argument parsing issue causing Argon crashes in specific contexts

Author: jacopodl

argon/lang/parser2/parser2.cpp

@@ -2144,6 +2144,8 @@ Node *Parser::ParseFuncCall(Context *context, Node *left) {
             }
 
             arg = (ArObject *) this->ParseExpression(context, PeekPrecedence(TokenType::COMMA));
+            if (!arg)
+                throw ParserException(this->tkcur_.loc, kStandardError[0]);
 
             if (this->ParseFuncCallSpread(args, (Node *) arg.Get(), mode == 1))
                 mode = 1;