Bug#593803: libphobos-4.1-dev: std.c.linux.socket only works on X86

[Daniel Gibson <gibson@Mathematik.Uni-Marburg.de>]

Hi,

I just realised that (in every version of std.c.linux.socket I've looked 
 at, which includes the latest version in gdc hg and phobos svn trunk 
at dsource) the following functions and structs are missing:
* sendmsg() and recvmsg()
* struct msghdr and struct iovec
* struct cmsghdr and macros/functions to modify them
(these structs are to be used with sendmsg() recvmsg()).

This stuff should be added because
1. it just belongs to linux/socket.h so std.c.linux.socket should 
contain it as well
2. it's needed to pass file descriptors/sockets between processes (see 
http://www.wsinnovations.com/softeng/articles/uds.html "File Descriptor 
Passing")

Cheers,
- Daniel