cmake HAVE_IPPROTO_IPV6 examples

arkdb/inception cmake/os/Windows.cmake :129

CHECK_SYMBOL_EXISTS(IPPROTO_IPV6 "winsock2.h" HAVE_IPPROTO_IPV6)

google/mysql-protobuf cmake/os/Windows.cmake :142

CHECK_SYMBOL_EXISTS(IPPROTO_IPV6 "winsock2.h" HAVE_IPPROTO_IPV6)

alibaba/AliSQL cmake/os/Windows.cmake :140

CHECK_SYMBOL_EXISTS(IPPROTO_IPV6 "winsock2.h" HAVE_IPPROTO_IPV6)

Tokutek/mysql-5.5 cmake/os/Windows.cmake :137

CHECK_SYMBOL_EXISTS(IPPROTO_IPV6 "winsock2.h" HAVE_IPPROTO_IPV6)