Fix for PR #9729, 9664, 9656, 8667.

All compilers on Solaris should build this extension correctly now.
It turns out the SUN CC, by default, enables a define that enables the use of
#pragma redefine extname in sun header files. This is why cc would work,
and gcc wouldn't.

-Jason

ext/sockets/sockets.c

@@ -35,6 +35,10 @@
 #define _XPG4_2
 #define __EXTENSIONS__
 
+#ifndef __PRAGMA_REDEFINE_EXTNAME
+#define __PRAGMA_REDEFINE_EXTNAME
+#endif
+
 #include "ext/standard/info.h"
 #include "php_sockets.h"
 #include "php_ini.h"