patch 8.1.0434: copy_loclist() is too long

Problem:    copy_loclist() is too long.
Solution:   Split in multiple functions. (Yegappan Lakshmanan)
diff --git a/src/window.c b/src/window.c
index a481af8..b50d835 100644
--- a/src/window.c
+++ b/src/window.c
@@ -1308,7 +1308,7 @@
 	newp->w_llist_ref = NULL;
     }
     else
-	copy_loclist(oldp, newp);
+	copy_loclist_stack(oldp, newp);
 #endif
     newp->w_localdir = (oldp->w_localdir == NULL)
 				    ? NULL : vim_strsave(oldp->w_localdir);