patch 9.0.2170: Vim9: no support for const/final class/objects vars

Problem:  Vim9: no support for const/final class/objects vars
Solution: Support final and const object and class variables

closes: #13655

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/structs.h b/src/structs.h
index de02bc6..3b51e0c 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -1523,14 +1523,18 @@
     VIM_ACCESS_ALL	// read/write everywhere
 } omacc_T;
 
+#define OCMFLAG_HAS_TYPE	0x01	// type specified explicitly
+#define OCMFLAG_FINAL		0x02	// "final" object/class member
+#define OCMFLAG_CONST		0x04	// "const" object/class member
+
 /*
  * Entry for an object or class member variable.
  */
 typedef struct {
     char_u	*ocm_name;	// allocated
     omacc_T	ocm_access;
-    int		ocm_has_type;	// type specified explicitly
     type_T	*ocm_type;
+    int		ocm_flags;
     char_u	*ocm_init;	// allocated
 } ocmember_T;