cmake HAVE_XCB_XLIB_H examples

Rezonality/zep demos/demo_imgui/clip/CMakeLists.txt :40 

check_include_files(xcb/xcb.h HAVE_XCB_XLIB_H)

Rezonality/zep demos/demo_imgui/clip/CMakeLists.txt :43 

add_definitions(-DHAVE_XCB_XLIB_H)