pytorch

93cd05b0 - Fix CMake errors on systems where {Q/X}NNPACK is not supported (#35607)

Fix CMake errors on systems where {Q/X}NNPACK is not supported (#35607) Summary: - add a couple of checks for USE_XNNPACK to disable additional code paths if XNNPACK is not supported When passing through the code paths where the platform checks are made (cmake/Dependencies.cmake:89), if XNNPACK is not supported, then the var FXDIV_SOURCE_DIR will not be set. CMake emits the errors when add_directory is called and FXDIV_SOURCE_DIR is empty. see: https://github.com/pytorch/pytorch/issues/34606 Pull Request resolved: https://github.com/pytorch/pytorch/pull/35607 Differential Revision: D20895645 Pulled By: seemethere fbshipit-source-id: 3bd10cf89f0fb6825fdd6e1d52c71ee37c67b953