[Win32] Define some Socket-related %Config keys

Affects only mingw-w64 builds of perl. Fixes:
StrawberryPerl/Perl-Dist-Strawberry#221

win32/config.gc

@@ -233,10 +233,10 @@ d_fsync='undef'
 d_ftello='undef'
 d_ftime='define'
 d_futimes='undef'
-d_gai_strerror='undef'
+d_gai_strerror='define'
 d_gdbm_ndbm_h_uses_prototypes='undef'
 d_gdbmndbm_h_uses_prototypes='undef'
-d_getaddrinfo='undef'
+d_getaddrinfo='define'
 d_getcwd='define'
 d_getenv_preserves_other_thread='define'
 d_getespwnam='undef'
@@ -259,7 +259,7 @@ d_getlogin='define'
 d_getlogin_r='undef'
 d_getmnt='undef'
 d_getmntent='undef'
-d_getnameinfo='undef'
+d_getnameinfo='define'
 d_getnbyaddr='undef'
 d_getnbyname='undef'
 d_getnent='undef'
@@ -311,9 +311,9 @@ d_inetaton='undef'
 d_inetntop='define'
 d_inetpton='define'
 d_int64_t='undef'
-d_ip_mreq='undef'
-d_ip_mreq_source='undef'
-d_ipv6_mreq='undef'
+d_ip_mreq='define'
+d_ip_mreq_source='define'
+d_ipv6_mreq='define'
 d_ipv6_mreq_source='undef'
 d_isascii='define'
 d_isblank='undef'
@@ -535,7 +535,7 @@ d_sigsetjmp='undef'
 d_sin6_scope_id='define'
 d_sitearch='define'
 d_snprintf='define'
-d_sockaddr_in6='undef'
+d_sockaddr_in6='define'
 d_sockaddr_sa_len='undef'
 d_sockaddr_storage='define'
 d_sockatmark='undef'

win32/config_H.gc

@@ -1943,12 +1943,12 @@
 #define	HAS_SOCKET		/**/
 /*#define	HAS_SOCKETPAIR	/ **/
 /*#define	HAS_SOCKADDR_SA_LEN	/ **/
-/*#define	HAS_SOCKADDR_IN6	/ **/
+#define	HAS_SOCKADDR_IN6	/**/
 #define	HAS_SOCKADDR_STORAGE	/**/
 #define	HAS_SIN6_SCOPE_ID	/**/
-/*#define	HAS_IP_MREQ	/ **/
-/*#define	HAS_IP_MREQ_SOURCE	/ **/
-/*#define	HAS_IPV6_MREQ	/ **/
+#define	HAS_IP_MREQ	/**/
+#define	HAS_IP_MREQ_SOURCE	/**/
+#define	HAS_IPV6_MREQ	/**/
 /*#define	HAS_IPV6_MREQ_SOURCE	/ **/
 
 /* USE_STAT_BLOCKS:
@@ -2712,13 +2712,13 @@
  *	is available to translate error codes returned by getaddrinfo()
  *	into human readable strings.
  */
-/*#define HAS_GAI_STRERROR	/ **/
+#define HAS_GAI_STRERROR	/**/
 
 /* HAS_GETADDRINFO:
  *	This symbol, if defined, indicates that the getaddrinfo() function
  *	is available for use.
  */
-/*#define HAS_GETADDRINFO		/ **/
+#define HAS_GETADDRINFO		/**/
 
 /* HAS_GETCWD:
  *	This symbol, if defined, indicates that the getcwd routine is
@@ -2760,7 +2760,7 @@
  *	This symbol, if defined, indicates that the getnameinfo() function
  *	is available for use.
  */
-/*#define HAS_GETNAMEINFO		/ **/
+#define HAS_GETNAMEINFO		/**/
 
 /* HAS_GETPRPWNAM:
  *	This symbol, if defined, indicates that the getprpwnam system call is