Commit 5736658b ("udp: add flag to enable recvmmsg(2) explicitly") added
the flag but didn't update the validation logic in src/win/udp.c.
This commit moves the validation logic to src/uv-common.c. The flag is
now accepted as a no-op on Windows.
Fixes: https://github.com/libuv/libuv/issues/2806
PR-URL: https://github.com/libuv/libuv/pull/2809
Reviewed-By: Bartosz Sosnowski <bartosz@janeasystems.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
aa7b62efd9