__BEGIN_DECLS/__END_DECLS are BSD specific and not defined in musl
glibc and uclibc had sys/cdefs.h doing it.

Upstream-Status: Inactive-Upstream [current release is from 1997; no vcs anywhere]
Signed-off-by: Khem Raj <raj.khem@gmail.com>

Index: tcp_wrappers_7.6/tcpd.h
===================================================================
--- tcp_wrappers_7.6.orig/tcpd.h
+++ tcp_wrappers_7.6/tcpd.h
@@ -11,7 +11,9 @@
 #include <netinet/in.h>
 #include <stdio.h>
 
-__BEGIN_DECLS
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 /* Structure to describe one communications endpoint. */
 
@@ -252,6 +254,8 @@ extern char *fix_strtok();
 extern char *my_strtok();
 #endif
 
-__END_DECLS
+#ifdef __cplusplus
+}
+#endif
 
 #endif
