cmake HAVE_SIGSET examples

SWI-Prolog/swipl-devel cmake/Config.cmake :222 

check_function_exists(sigset HAVE_SIGSET)

arkdb/inception configure.cmake :473 

CHECK_FUNCTION_EXISTS (sigset HAVE_SIGSET)

alibaba/AliSQL configure.cmake :580 

CHECK_FUNCTION_EXISTS (sigset HAVE_SIGSET)

Tokutek/mysql-5.5 configure.cmake :413 

CHECK_FUNCTION_EXISTS (sigset HAVE_SIGSET)