Fix crash on failure to read bytecode (penneryu)

quickjs.c

@@ -34924,6 +34924,7 @@ static void free_function_bytecode(JSRuntime *rt, JSFunctionBytecode *b)
                JS_AtomGetStrRT(rt, buf, sizeof(buf), b->func_name));
     }
 #endif
+    if (b->byte_code_buf)
         free_bytecode_atoms(rt, b->byte_code_buf, b->byte_code_len, TRUE);
 
     if (b->vardefs) {