Re: add sendmmsg and recvmmsg systemcalls

[Stuart Henderson]

btw a few ports will likely pick this up:

paths/devel/glib2.log:Checking for function "recvmmsg" : NO
paths/net/tinc.log:checking for recvmmsg... no
paths/net/knot.log:checking for recvmmsg... no
paths/net/knot.log:    Use recvmmsg:           no
paths/net/gdnsd.log:checking whether recvmmsg is declared... no
paths/net/gdnsd.log:checking for recvmmsg... no
paths/net/powerdns.log:checking for recvmmsg... no
paths/net/powerdns.log:checking for recvmmsg... (cached) no
paths/net/dnsdist.log:checking for recvmmsg... no
paths/net/powerdns_recursor.log:checking for recvmmsg... no
paths/sysutils/rsyslog,-elasticsearch.log:checking for recvmmsg... no