pgsql: Avoid calling TestLib::perl2host on a symlinked directory

Avoid calling TestLib::perl2host on a symlinked directory

Certain versions of msys2/Windows have been observed to resolve symlinks
in perl2host rather than just follow them. This defeats using a
symlinked shorter path to a longer path, and makes certain tests fail.
We therefore call perl2host on the parent directory of the symlink and
thereafter just use that result.

Apply to release 14 where the problem has been observed.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/b35a67bc04243da609843949c53e6841e748243a

Modified Files
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src/bin/pg_basebackup/t/010_pg_basebackup.pl | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)