[llvm] [Doc] update the usage of opt with mem2reg pass in tutorial (PR #76282)

[via llvm-commits]

https://github.com/youkaichao created https://github.com/llvm/llvm-project/pull/76282

The current command will raise an error:

> The `opt -passname` syntax for the new pass manager is not supported, please use `opt -passes=<pipeline>` (or the `-p` alias for a more concise version).

So we should update the usage.

>From 94a336f68b5cce228ff29ec05e766b64beaaaf41 Mon Sep 17 00:00:00 2001
From: youkaichao <youkaichao at gmail.com>
Date: Sat, 23 Dec 2023 17:59:49 +0800
Subject: [PATCH] update the usage of opt with mem2reg pass

---
 llvm/docs/tutorial/MyFirstLanguageFrontend/LangImpl07.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/docs/tutorial/MyFirstLanguageFrontend/LangImpl07.rst b/llvm/docs/tutorial/MyFirstLanguageFrontend/LangImpl07.rst
index 0347127d0cdf1d..8fd4c39d3ff47b 100644
--- a/llvm/docs/tutorial/MyFirstLanguageFrontend/LangImpl07.rst
+++ b/llvm/docs/tutorial/MyFirstLanguageFrontend/LangImpl07.rst
@@ -182,7 +182,7 @@ example through the pass, for example, you'll get:
 
 .. code-block:: bash
 
-    $ llvm-as < example.ll | opt -mem2reg | llvm-dis
+    $ llvm-as < example.ll | opt -passes=mem2reg | llvm-dis
     @G = weak global i32 0
     @H = weak global i32 0