cmake SAIL_HAVE_ALIGNAS examples

HappySeaFox/sail cmake/sail_check_alignas.cmake :14 

try_compile(SAIL_HAVE_ALIGNAS
                ${CMAKE_CURRENT_BINARY_DIR}
                ${CMAKE_CURRENT_BINARY_DIR}/sail_check_alignas.c
                C_STANDARD 11
                C_STANDARD_REQUIRED ON)