Fix some bugs in lexer

src/main.c

@@ -52,11 +52,11 @@ parser_run (const char *script_source, size_t script_source_size, bool is_show_o
   offset = serializer_dump_strings (strings, strings_num);
   serializer_dump_nums (nums, nums_count, offset, strings_num);
   
-  lexer_free ();
-
   parser_init ();
   parser_parse_program ();
 
+  lexer_free ();
+
   opcodes = deserialize_bytecode ();
 
   optimizer_run_passes ((OPCODE *) opcodes);