[PATCH v3 1/2] newlib/libc/include/devctl.h: Add extern "C" wrapper

Adding this was necessary to allow posix_devctl() from C++.
---
 newlib/libc/include/devctl.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/newlib/libc/include/devctl.h b/newlib/libc/include/devctl.h
index fd3409f..889693e 100644
--- a/newlib/libc/include/devctl.h
+++ b/newlib/libc/include/devctl.h
@@ -35,6 +35,10 @@
 
 #include <sys/cdefs.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #if defined(__rtems__)
 /*
  * The FACE Technical Standard, Edition 3.0 and later require the
@@ -67,4 +71,8 @@ int posix_devctl(
 );
 #endif
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif
-- 
1.8.3.1