Directly use the __DEPRECATED token to avoid warnings about

deprecated headers coming from VTK.  This works for GCC, and
the __DEPRECATED token has been used at least as far back
as GCC 4.2.

src/mesh/vtk_io.C

@@ -37,6 +37,22 @@
 #ifdef LIBMESH_HAVE_VTK
 
 #include "libmesh/ignore_warnings.h"
+
+// Hack to avoid warnings coming from stupid VTK files that include
+// deprecated headers.  We only do this for GCC >= 4.2, but it may
+// work for other compilers as well.  Note: technically it is
+// illegal to mess with identifiers that have double leading
+// underscores... but it is also technically super annoying to see
+// this warning all the time.
+#if defined(__GNUC__) && !defined(__INTEL_COMPILER) && !defined(__clang__)
+#if __GNUC__ > 3 && __GNUC_MINOR__ > 1
+#ifdef __DEPRECATED
+  #undef __DEPRECATED
+  #define LIBMESH_REDEFINE_DEPRECATED
+#endif // if __DEPRECATED
+#endif // if version
+#endif // if gnu
+
 #include "vtkXMLUnstructuredGridReader.h"
 #include "vtkXMLUnstructuredGridWriter.h"
 #include "vtkXMLPUnstructuredGridWriter.h"
@@ -48,6 +64,11 @@
 #include "vtkPointData.h"
 #include "vtkPoints.h"
 #include "vtkSmartPointer.h"
+
+#ifdef LIBMESH_REDEFINE_DEPRECATED
+  #define __DEPRECATED
+#endif
+
 #include "libmesh/restore_warnings.h"
 
 // A convenient macro for comparing VTK versions.  Returns 1 if the