fix on uClibc without IPv6 support

Signed-off-by: Francois Perrad <francois.perrad@gadz.org>

Index: b/cpan/Socket/Socket.xs
===================================================================
--- a/cpan/Socket/Socket.xs
+++ b/cpan/Socket/Socket.xs
@@ -896,7 +896,7 @@
 	CODE:
 #ifdef HAS_INETNTOP
 	STRLEN addrlen;
-#ifdef AF_INET6
+#if (defined(__UCLIBC__) && defined(__UCLIBC_HAS_IPV6__)) || (!defined(__UCLIBC__) && defined(AF_INET6))
 	struct in6_addr addr;
 	char str[INET6_ADDRSTRLEN];
 #else
@@ -916,7 +916,7 @@
 		croak("Bad address length for Socket::inet_ntop on AF_INET;"
 		      " got %"UVuf", should be 4", (UV)addrlen);
 	    break;
-#ifdef AF_INET6
+#if (defined(__UCLIBC__) && defined(__UCLIBC_HAS_IPV6__)) || (!defined(__UCLIBC__) && defined(AF_INET6))
 	  case AF_INET6:
 	    if(addrlen != 16)
 		croak("Bad address length for Socket::inet_ntop on AF_INET6;"
@@ -925,7 +925,7 @@
 #endif
 	  default:
 		croak("Bad address family for %s, got %d, should be"
-#ifdef AF_INET6
+#if (defined(__UCLIBC__) && defined(__UCLIBC_HAS_IPV6__)) || (!defined(__UCLIBC__) && defined(AF_INET6))
 		      " either AF_INET or AF_INET6",
 #else
 		      " AF_INET",
@@ -955,7 +955,7 @@
 #ifdef HAS_INETPTON
 	int ok;
 	int addrlen = 0;
-#ifdef AF_INET6
+#if (defined(__UCLIBC__) && defined(__UCLIBC_HAS_IPV6__)) || (!defined(__UCLIBC__) && defined(AF_INET6))
 	struct in6_addr ip_address;
 #else
 	struct in_addr ip_address;
@@ -965,14 +965,14 @@
 	  case AF_INET:
 	    addrlen = 4;
 	    break;
-#ifdef AF_INET6
+#if (defined(__UCLIBC__) && defined(__UCLIBC_HAS_IPV6__)) || (!defined(__UCLIBC__) && defined(AF_INET6))
 	  case AF_INET6:
 	    addrlen = 16;
 	    break;
 #endif
 	  default:
 		croak("Bad address family for %s, got %d, should be"
-#ifdef AF_INET6
+#if (defined(__UCLIBC__) && defined(__UCLIBC_HAS_IPV6__)) || (!defined(__UCLIBC__) && defined(AF_INET6))
 		      " either AF_INET or AF_INET6",
 #else
 		      " AF_INET",