cmake _HAS_MANGLING_TEST examples

Kitware/VTK CMake/vtkModuleTesting.cmake :1105 

get_property(has_test GLOBAL PROPERTY "${module}_HAS_MANGLING_TEST" SET)

Kitware/VTK CMake/vtkModuleTesting.cmake :1108 

set_property(GLOBAL PROPERTY "${module}_HAS_MANGLING_TEST" 1)