patch 8.2.3890: Vim9: type check for using v: variables is basic

Problem:    Vim9: type check for using v: variables is basic.
Solution:   Specify a more precise type.
diff --git a/src/vim9instr.c b/src/vim9instr.c
index 06d6b90..0468f33 100644
--- a/src/vim9instr.c
+++ b/src/vim9instr.c
@@ -946,8 +946,7 @@
 	    semsg(_(e_variable_not_found_str), name);
 	return FAIL;
     }
-    type = typval2type_vimvar(get_vim_var_tv(vidx), cctx->ctx_type_list);
-
+    type = get_vim_var_type(vidx, cctx->ctx_type_list);
     return generate_LOAD(cctx, ISN_LOADV, vidx, NULL, type);
 }