Moving the ffi_build file into the xkbcommon module, which allows the
FFI object to be imported in dependent cffi-based projects. This is
needed in particular by the pywlroots project to be able to make
xkb_keyboard objects usable in the wlroots API.
Moving the ffi_build file into the xkbcommon module, which allows the FFI object to be imported in dependent cffi-based projects. This is needed in particular by the pywlroots project to be able to make xkb_keyboard objects usable in the wlroots API.