Merge topic 'fix-Wstrict-prototypes'

81022213f6 Modules: Fix clang -Wstrict-prototypes warnings
47c3334203 Source: Fix clang -Wstrict-prototypes warnings
264dcae5e4 Tests: Fix clang -Wstrict-prototypes warnings

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !8916