cmake HAVE_ATOMICS_64_SYNC examples

fluent/fluent-bit lib/librdkafka-2.10.1/packaging/cmake/try_compile/rdkafka_setup.cmake :98 

try_compile(
        HAVE_ATOMICS_64_SYNC
        "${CMAKE_CURRENT_BINARY_DIR}/try_compile"
        "${TRYCOMPILE_SRC_DIR}/sync_64_test.c"
    )