cmake HAVE_FILESYSTEM_IN_STDEXPERIMENTAL examples

PacktPublishing/The-Modern-Vulkan-Cookbook source/chapter8/app/src/main/cpp/thirdparty/OpenXR-SDK/src/cmake/StdFilesystemFlags.cmake :114 

check_cxx_source_compiles("${_stdfs_experimental_source}" HAVE_FILESYSTEM_IN_STDEXPERIMENTAL)

rbfx/rbfx Source/ThirdParty/OpenXRSDK/src/cmake/StdFilesystemFlags.cmake :114 

check_cxx_source_compiles("${_stdfs_experimental_source}" HAVE_FILESYSTEM_IN_STDEXPERIMENTAL)

RavEngine/RavEngine deps/OpenXR-SDK/src/cmake/StdFilesystemFlags.cmake :114 

check_cxx_source_compiles("${_stdfs_experimental_source}" HAVE_FILESYSTEM_IN_STDEXPERIMENTAL)