cmake HAVE_ATOMIC_SWAP_UCHAR examples

alibaba/AliSQL storage/innobase/CMakeLists.txt :226 

CHECK_FUNCTION_EXISTS(atomic_swap_uchar HAVE_ATOMIC_SWAP_UCHAR)

Tokutek/mysql-5.5 storage/innobase/CMakeLists.txt :128 

CHECK_FUNCTION_EXISTS(atomic_swap_uchar HAVE_ATOMIC_SWAP_UCHAR)