* fhandler_disk_file.cc (__DIR_mounts::eval_ino): Create path_conv
with PC_KEEP_HANDLE flag.
* path.h (path_conv::operator =): Duplicate UNICODE path as well.
* security.cc (check_file_access): Use path_conv handle if available.
* syscalls.cc (access): Create fhandler with PC_KEEP_HANDLE flag set.
(euidaccess): Ditto.
(faccessat): Ditto.