Merge topic 'cxxmodules-collation-restat'

a7424b636b Ninja: make the collator rule use `restat = 1`
e24eecfc33 Tests/CXXModules: add a test to ensure that `restat` works for collation

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !9259