Update Gnulib to v0.1-603-g1d16a7b

lib/dirname.h

@@ -1,6 +1,6 @@
 /*  Take file names apart into directory and base names.
 
-    Copyright (C) 1998, 2001, 2003-2006, 2009-2014 Free Software Foundation,
+    Copyright (C) 1998, 2001, 2003-2006, 2009-2015 Free Software Foundation,
     Inc.
 
     This program is free software: you can redistribute it and/or modify
@@ -31,6 +31,10 @@
 #  define DOUBLE_SLASH_IS_DISTINCT_ROOT 0
 # endif
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 # if GNULIB_DIRNAME
 char *base_name (char const *file);
 char *dir_name (char const *file);
@@ -43,4 +47,8 @@ char *last_component (char const *file) _GL_ATTRIBUTE_PURE;
 
 bool strip_trailing_slashes (char *file);
 
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
 #endif /* not DIRNAME_H_ */