Merge topic 'GenerateExportHeader-Fix-Clang-support-on-Windows'

1e19936320 GenerateExportHeader: Fix Clang support on Windows

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Adrien De Coninck <deconinck.adrien@gmail.com>
Merge-request: !8221