patch 9.0.2184: Vim9: inconsistent :type/:class messages

Problem:  Vim9: inconsistent :type/:class messages
Solution: Update the Messages (Ernie Rael)

closes: #13706

Signed-off-by: Ernie Rael <errael@raelity.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/evalvars.c b/src/evalvars.c
index 64455f0..ea039cb 100644
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -3974,12 +3974,8 @@
 		goto failed;
 	    }
 
-	    if (di->di_tv.v_type == VAR_TYPEALIAS)
-	    {
-		semsg(_(e_cannot_modify_typealias),
-					    di->di_tv.vval.v_typealias->ta_name);
+	    if (check_typval_is_value(&di->di_tv) == FAIL)
 		goto failed;
-	    }
 
 	    if (var_in_vim9script && (flags & ASSIGN_FOR_LOOP) == 0)
 	    {