Check for struct addrinfo availability. Patch by Martin Storsjö

<$firstname()$firstname,st>.

Originally committed as revision 21144 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -989,6 +989,7 @@ HAVE_LIST="
     socklen_t
     soundcard_h
     poll_h
+    struct_addrinfo
     sys_mman_h
     sys_resource_h
     sys_select_h
@@ -2449,6 +2450,7 @@ texi2html -version > /dev/null 2>&1 && enable texi2html || disable texi2html
 
 if enabled network; then
     check_type "sys/types.h sys/socket.h" socklen_t
+    check_type netdb.h "struct addrinfo"
     # Prefer arpa/inet.h over winsock2
     if check_header arpa/inet.h ; then
         check_func closesocket
@@ -2458,6 +2460,7 @@ if enabled network; then
         { check_func_headers winsock2.h closesocket -lws2_32 && \
             network_extralibs="-lws2_32"; }
         check_type ws2tcpip.h socklen_t
+        check_type ws2tcpip.h "struct addrinfo"
     else
         disable network
     fi