plug-ins: Silence 'register' storage class specifier warning on Clang too

plug-ins/file-exr/openexr-wrapper.cc

@@ -19,8 +19,6 @@
 
 #include <string>
 
-#include <lcms2.h>
-
 /*  These libgimp includes are not needed here at all, but this is a
  *  convenient place to make sure the public libgimp headers are
  *  C++-clean. The C++ compiler will choke on stuff like naming
@@ -51,13 +49,20 @@
 /* ignore deprecated warnings from OpenEXR headers */
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wdeprecated"
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-register"
+
+#include <lcms2.h>
+
 #include <ImfInputFile.h>
 #include <ImfChannelList.h>
 #include <ImfRgbaFile.h>
 #include <ImfArray.h>
 #include <ImfRgbaYca.h>
 #include <ImfStandardAttributes.h>
+
 #pragma GCC diagnostic pop
+#pragma clang diagnostic pop
 
 #include "exr-attribute-blob.h"
 #include "openexr-wrapper.h"