Add OpenSolaris compatibility definitions for stat64 and fstat64 which

are only visible if _SOLARIS_C_SOURCE is defined.

Note thar FreeBSD stat() and fstat() are 64-bit functions now and Solaris
still persists with both 32- and 64-bit versions. When I query this, I am
referred to: <http://www.unix.org/version2/whatsnew/lfs20mar.html>.
But when you look at the main page of unix.org you will see that the
Single Unix Specification <http://www.unix.org/version3/> is the most
recent standard they are pushing. And there are no stat64() fstat64()
functions defined there. I guess this just goes to prove that there are so
many standards, you can take your pick.

sys/sys/stat.h

@@ -304,6 +304,14 @@ struct nstat {
 
 #endif /* __BSD_VISIBLE */
 
+/*
+ * Solaris compatibility definitions.
+ */
+#ifdef _SOLARIS_C_SOURCE
+#define	stat64	stat
+#define	fstat64	fstat
+#endif
+
 #ifndef _KERNEL
 __BEGIN_DECLS
 #if __BSD_VISIBLE