Merge topic 'realpath-windows' into release-4.0

0a5efe8489 cmSystemTools: Fix GetRealPath implementation on Windows
5910bf0b40 cmSystemTools: Restore GetRealPathResolvingWindowsSubst

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: buildbot <buildbot@kitware.com>
Merge-request: !10452