Lkt lowering: handle iterator types

TN: RA22-015

Author: pmderodat

langkit/lkt_lowering.py

@@ -1224,6 +1224,10 @@ def resolve_type_decl(self, decl: L.TypeDecl) -> CompiledTypeOrDefer:
                 assert len(actuals) == 1
                 result = self.resolve_type_decl(actuals[0]).array
 
+            elif inner_type == self.iterator_trait:
+                assert len(actuals) == 1
+                result = self.resolve_type_decl(actuals[0]).iterator
+
             elif inner_type == self.astlist_type:
                 assert len(actuals) == 1
                 node = self.resolve_type_decl(actuals[0])

testsuite/tests/iterators/int_iterator/test.py

@@ -31,5 +31,5 @@ def iterator_identity(it=T.Int.iterator):
 build_and_run(lkt_file='expected_concrete_syntax.lkt',
               py_script='main.py',
               ada_main='main.adb',
-              lkt_semantic_checks=True)
+              types_from_lkt=True)
 print('Done')