cmake HAVE_THR_SETCONCURRENCY examples

arkdb/inception configure.cmake :501 

CHECK_FUNCTION_EXISTS (thr_setconcurrency HAVE_THR_SETCONCURRENCY)

alibaba/AliSQL configure.cmake :608 

CHECK_FUNCTION_EXISTS (thr_setconcurrency HAVE_THR_SETCONCURRENCY)

Tokutek/mysql-5.5 configure.cmake :441 

CHECK_FUNCTION_EXISTS (thr_setconcurrency HAVE_THR_SETCONCURRENCY)