os.file: Fix os file tell for windows

[kbkpbot]

Fix issue #24217

[huly-for-github]

Connected to Huly®: V_0.6-22601

[kbkpbot]

It seems that fd and cfile maintain their own position pointer.
If file is opened in buffer mode, these pointer may de-synchronize.

fd := C._wopen(p.to_wide(), flags, permission);

cfile := C.fdopen(fd, &char(mode.str));

C._fseeki64(cfile, 0, C.SEEK_END);

x := C._telli64(fd);

y := C._ftelli64(cfile);

// x y may different, not sure.

[spytheman]

@kbkpbot, 3354c11 passed the CI, can we merge it?

[kbkpbot]

I think this PR can merge now.

[spytheman]

Excellent work.
I tried with msvc, clang, gcc, and tcc, all worked.

[spytheman]