Some `phpt` file names are not recognized by `kphp_tester.py`

[mkornaukhov03]

For example:

1. I add new phpt file with the following path: tests/phpt/constants/006_object_as_class_const.php.
2. Then I do $ ./kphp_tester.py 006_object_as_class_const.php.
3. After that, I see Can't find any tests with [006_object_as_class_const.php] tag
4. Rename file to tests/phpt/constants/006_oacc.php
5. Launch $ ./kphp_tester.py 006_oacc.php
6. It's succeed