Description:
------------
It seems that fopen_for_include uses runtime encoding, not filesystem encoding.

Reproduce code:
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php.ini
-------
unicode_semantics = on
unicode.output_encoding = utf-8
unicode.runtime_encoding = iso-8859-1
unicode.script_encoding = utf-8
unicode.filesystem_encoding = utf-8

f.php
-----
<?php include "caf?.php"; >

caf?.php (UTF-8 name)
---------------------
<?php echo "in caf?\n"; ?>


Expected result:
----------------
in caf?

Actual result:
--------------
Warning: include(caf?.php): failed to open stream: No such file or directory in /home/andrei/dev/php-src/f.php on line 1

Warning: include(): Failed opening 'caf?.php' for inclusion (include_path='.') in /home/andrei/dev/php-src/f.php on line 1