cmake BSON_HAVE_RAND_R examples

cvet/fonline ThirdParty/mongo-c-driver/src/libbson/CMakeLists.txt :94 

check_function_exists (rand_r BSON_HAVE_RAND_R)

realm/realm-core src/external/bson/CMakeLists.txt :36 

check_function_exists (rand_r BSON_HAVE_RAND_R)