pg_rewind fails on Windows where tablespaces are used

Hi,

Setup is PostgreSQL on Windows with a tablespace on a separate drive. When
I go to run pg_rewind it consistently fails with the following error:

pg_rewind: servers diverged at WAL location 39B/7EC6F60 on timeline 2
pg_rewind: rewinding from last common checkpoint at 39B/7E8E3F8 on timeline
2
pg_rewind: error: file "pg_tblspc/34244696" is of different type in source
and target

The file is confirmed to be a JUNCTION to the correct location on both the
source and target. So the error looks like a problem interacting with
Windows and detecting JUNCTION types in this case.

I came across the following which looks like it would fix this problem but
don't have a proper build environment. Please consider backporting the fix
at least as far as Postgres 15 as this bug fix does apply to non-in-place
tablespaces on Windows. The thread is
https://postgrespro.com/list/thread-id/2657122

Best Regards,
Chris Travers