[tz] zic.c's dolink() fails on some Windows filesystems

I have a report[1] that tzcode 2026b fails on Windows filesystems that lack hard links, because it copes if link() fails with ENOTSUP but what is actually returned is EINVAL. I suggest something along the lines of if (link(target, outname) == 0) { link_errno = 0; break; } link_errno = errno; + /* Windows returns EINVAL if filesystem lacks hard links. */ + if (link_errno == EINVAL) + link_errno = ENOTSUP; } paralleling the workaround for ancient Linux a few lines above. regards, tom lane [1] https://www.postgresql.org/message-id/e6122f9b2eef9096f1f11ecc058bcd91%40pos...