clover: Fix the const variant of adaptor_range::end to deal with mismatching range sizes.

Fixes infinite loop in find_grid_optimal_factor() in cases where the
user specifies a grid size with less dimensions than the device
supports.

Reported-by: Tom Stellard <thomas.stellard@amd.com>
Cc: "10.0" <mesa-stable@lists.freedesktop.org>

src/gallium/state_trackers/clover/util/range.hpp

@@ -269,7 +269,8 @@ namespace clover {
 
       typename super::const_iterator
       end() const {
-         return { f, tuple::map(ends(), os) };
+         return { f, tuple::map(advances_by(size()),
+                                tuple::map(begins(), os)) };
       }
 
       typename super::size_type