cmake _HAVE_WAITPID examples

HDFGroup/hdf5 config/ConfigureChecks.cmake :440 

CHECK_FUNCTION_EXISTS (waitpid           ${HDF_PREFIX}_HAVE_WAITPID)

InsightSoftwareConsortium/ITK Modules/ThirdParty/HDF5/src/itkhdf5/config/cmake/ConfigureChecks.cmake :426 

CHECK_FUNCTION_EXISTS (waitpid           ${HDF_PREFIX}_HAVE_WAITPID)

Tencent/Forward source/third_party/hdf5/config/cmake_ext_mod/ConfigureChecks.cmake :531 

CHECK_FUNCTION_EXISTS (waitpid           ${HDF_PREFIX}_HAVE_WAITPID)

Kitware/VTK ThirdParty/hdf5/vtkhdf5/config/cmake_ext_mod/ConfigureChecks.cmake :463 

CHECK_FUNCTION_EXISTS (waitpid           ${HDF_PREFIX}_HAVE_WAITPID)