[llvm] [llvm][nfc] Ignore OpenAI Codex artifacts (PR #162481)

[Cullen Rhodes via llvm-commits]

https://github.com/c-rhodes updated https://github.com/llvm/llvm-project/pull/162481

>From 243d9c6bf3a48f79d6e19fc82e75c40cb2f3e015 Mon Sep 17 00:00:00 2001
From: Cullen Rhodes <cullen.rhodes at arm.com>
Date: Wed, 8 Oct 2025 13:13:28 +0000
Subject: [PATCH] [llvm][nfc] Ignore OpenAI Codex artifacts

Follow-up to #153853 to also ignore Codex artifacts [1]. AGENTS.md may
be at the root or in sub-directories, so unlike other Markdown config
files I've not prefixed it with '/' to support this.

[1] https://github.com/openai/codex/blob/main/docs/getting-started.md#memory-with-agentsmd
---
 .gitignore | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/.gitignore b/.gitignore
index a9d616286adf1..f62d3dde8caed 100644
--- a/.gitignore
+++ b/.gitignore
@@ -57,6 +57,8 @@ autoconf/autom4te.cache
 .claude/
 /GEMINI.md
 .gemini/
+AGENTS.md
+.codex/
 
 #==============================================================================#
 # Directories to ignore (do not add trailing '/'s, they skip symlinks).