RT2308: Add extern "C" { ... } wrapper

Add the wrapper to all public header files (Configure
generates one).  Don't bother for those that are just
lists of #define's that do renaming.

Reviewed-by: Tim Hudson <tjh@openssl.org>

(cherry picked from commit 089f10e69e)

crypto/stack/safestack.h

@@ -57,6 +57,10 @@
 
 #include <openssl/stack.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #ifndef CHECKED_PTR_OF
 #define CHECKED_PTR_OF(type, p) \
     ((void*) (1 ? p : (type*)0))
@@ -2660,4 +2664,8 @@ DECLARE_SPECIAL_STACK_OF(OPENSSL_BLOCK, void)
 #define lh_SSL_SESSION_free(lh) LHM_lh_free(SSL_SESSION,lh)
 /* End of util/mkstack.pl block, you may now edit :-) */
 
+
+#ifdef  __cplusplus
+}
+#endif
 #endif /* !defined HEADER_SAFESTACK_H */