Merge topic 'cxxmodules-refactor-detection-support'

e37ff5694c cmGeneratorTarget: factor out fileset info and scanning detection
9e61fc3d6d cmGeneratorTarget: factor out dyndep support detection
5e026739e1 cmGlobalGenerator: factor out C++ module support checking

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !7951