cmake KWSYS_CXX_HAS_DLFCNH examples

InsightSoftwareConsortium/ITK Modules/ThirdParty/KWSys/src/KWSys/CMakeLists.txt :518 

check_include_file_cxx("dlfcn.h" KWSYS_CXX_HAS_DLFCNH)

Kitware/kwiver vital/kwiversys/CMakeLists.txt :615 

CHECK_INCLUDE_FILE_CXX("dlfcn.h" KWSYS_CXX_HAS_DLFCNH)

Kitware/VTK Utilities/KWSys/vtksys/CMakeLists.txt :546 

CHECK_INCLUDE_FILE_CXX("dlfcn.h" KWSYS_CXX_HAS_DLFCNH)

ornladios/ADIOS2 thirdparty/KWSys/adios2sys/CMakeLists.txt :526 

CHECK_INCLUDE_FILE_CXX("dlfcn.h" KWSYS_CXX_HAS_DLFCNH)