cmake HAVE_FCITX_FRONTEND_H examples

inolen/redream deps/sdl2/CMakeLists.txt :947 

check_include_file("fcitx/frontend.h" HAVE_FCITX_FRONTEND_H)

google/filament third_party/libsdl2/CMakeLists.txt :1047 

check_include_file("fcitx/frontend.h" HAVE_FCITX_FRONTEND_H)

crossuo/crossuo deps/sdl-2.0.10-c1be3add38/CMakeLists.txt :1138 

check_include_file("fcitx/frontend.h" HAVE_FCITX_FRONTEND_H)