patch 8.2.0159: non-materialized range() list causes problems

Problem:    Non-materialized range() list causes problems. (Fujiwara Takuya)
Solution:   Materialize the list where needed.
diff --git a/src/evalvars.c b/src/evalvars.c
index 38cb457..cc4a70f 100644
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -843,6 +843,7 @@
 	return FAIL;
     }
 
+    range_list_materialize(l);
     item = l->lv_first;
     while (*arg != ']')
     {
@@ -1699,7 +1700,7 @@
 		    l->lv_lock |= VAR_LOCKED;
 		else
 		    l->lv_lock &= ~VAR_LOCKED;
-		if (deep < 0 || deep > 1)
+		if ((deep < 0 || deep > 1) && l->lv_first != &range_list_item)
 		    // recursive: lock/unlock the items the List contains
 		    for (li = l->lv_first; li != NULL; li = li->li_next)
 			item_lock(&li->li_tv, deep - 1, lock);