gpu: jit: conv: skip cast in is_nary_op_canonical()

Author: echeresh

src/gpu/jit/pass/simplify.cpp

@@ -816,6 +816,8 @@ class nary_op_canonical_verifier_t : public nary_op_visitor_t {
         }
     }
 
+    void _visit(const cast_t &obj) override { visit_new_scope(obj); }
+
     void _visit(const iif_t &obj) override { visit_new_scope(obj); }
 
     void _visit(const load_t &obj) override { visit_new_scope(obj); }