-mtc=on on Linux doesn't preserve Birth/Creation time

[qyot27]

Or rather, what it does is copy the Change time into the Birth/Creation field instead.

Original file on Linux, on ext4

$ stat test.webm 
  File: test.webm
Access: 2026-02-08 00:38:16.547324420 -0500
Modify: 2026-02-08 00:20:26.805612087 -0500
Change: 2026-02-08 00:20:37.295639713 -0500
 Birth: 2026-02-08 00:20:37.268639642 -0500

Packaged on Linux with 7-Zip 25.01 (7za a -mtc=on -mx9 test.7z test.webm), then unpacked on Windows:

E:\Documents_C>stat "test.webm"
  File: test.webm
Access: 2026-02-08 00:42:54.402737500 -0500
Modify: 2026-02-08 00:20:26.805612000 -0500
Change: 2026-02-08 00:42:27.135135300 -0500
 Birth: 2026-02-08 00:20:37.295639700 -0500

I'm fully aware that restoring the date when unpacking the archive on Linux isn't possible, since the kernel doesn't support mutable btime/crtime (and rejected a patchset back in 2019 that would have allowed for that), but for those filesystems that do support that kind of timestamp, it would be better for -mtc=on to preserve it so it could be restored when unpacked on other OSes.