Use make_kernel to force entrypoint registration

---------

Co-authored-by: Jack Betteridge <43041811+JDBetteridge@users.noreply.github.com>

tsfc/loopy.py

@@ -246,9 +246,17 @@ def generate(impero_c, args, scalar_type, kernel_name="loopy_kernel", index_name
     domains = create_domains(ctx.index_extent.items())
 
     # Create loopy kernel
-    knl = lp.make_function(domains, instructions, data, name=kernel_name, target=target,
-                           seq_dependencies=True, silenced_warnings=["summing_if_branches_ops"],
-                           lang_version=(2018, 2), preambles=preamble)
+    knl = lp.make_kernel(
+        domains,
+        instructions,
+        data,
+        name=kernel_name,
+        target=target,
+        seq_dependencies=True,
+        silenced_warnings=["summing_if_branches_ops"],
+        lang_version=(2018, 2),
+        preambles=preamble
+    )
 
     # Prevent loopy interchange by loopy
     knl = lp.prioritize_loops(knl, ",".join(ctx.index_extent.keys()))