fix: get hidden/archive/system porps on file

[j3l11234]

Hi,

I read samba's source code carefully and found them placed the hidden/archive/system porps in the execution flag.
So we can infer the original attribute value from these flags.

The correspondence is as follows:

hidden - > o + x, (other has exec permission)
archive - > u + x, (owner has exec permission)
system - > g + x, (group has exec permission)

File has default 644 permission mask but directory has default 755 permission mask
So directory cant determine weather has hidden/archive/system porps

Source: https://gitlab.com/samba-team/samba/-/blob/84b5440eb4f3c10e2729e916d097f5af07150dcd/source3/libsmb/libsmb_stat.c#L67

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By the way, I also found the reason why the system.dos_attr.mode change from dos permissions mask to unix permission mask.
https://gitlab.com/samba-team/samba/-/commit/0fe9dc521#64c7de226f297840d2892b1c3d76cc68a56fbc72
This is one bug, and I have proposed merge request to the samba team to solve this problem.
https://gitlab.com/samba-team/samba/-/merge_requests/2056

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I appreciate you checking the code and merging as soon as possible. Because my nextcloud urgently needs this part of the fix. Thanks!