[clang] [analyzer] Use sed from the ToolBox on AIX (NFC) (PR #161242)

[Kelvin Li via cfe-commits]

https://github.com/kkwli created https://github.com/llvm/llvm-project/pull/161242

The change in https://github.com/llvm/llvm-project/commit/30402c7dea57d35ead80387c061cda6977ba98ef breaks the tests on AIX. This patch is to change to use the `sed` from AIX Toolbox instead of the default one which does not support `-r` and `-E`.

cc @dbartol 

>From 588143436a36bba93a831609880a94789656c259 Mon Sep 17 00:00:00 2001
From: Kelvin Li <kli at ca.ibm.com>
Date: Mon, 29 Sep 2025 13:11:00 -0400
Subject: [PATCH] [analyzer] Use sed from the ToolBox on AIX (NFC)

---
 .../expected-sarif/sarif-multi-file-diagnostics.c.sarif       | 2 +-
 clang/test/Analysis/lit.local.cfg                             | 4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/clang/test/Analysis/diagnostics/Inputs/expected-sarif/sarif-multi-file-diagnostics.c.sarif b/clang/test/Analysis/diagnostics/Inputs/expected-sarif/sarif-multi-file-diagnostics.c.sarif
index 85e710fc7bac3..501d27ca22361 100644
--- a/clang/test/Analysis/diagnostics/Inputs/expected-sarif/sarif-multi-file-diagnostics.c.sarif
+++ b/clang/test/Analysis/diagnostics/Inputs/expected-sarif/sarif-multi-file-diagnostics.c.sarif
@@ -141,4 +141,4 @@
     }
   ],
   "version": "[SARIF version]"
-}
\ No newline at end of file
+}
diff --git a/clang/test/Analysis/lit.local.cfg b/clang/test/Analysis/lit.local.cfg
index 3d60a16405ea6..03ab418a5a4f7 100644
--- a/clang/test/Analysis/lit.local.cfg
+++ b/clang/test/Analysis/lit.local.cfg
@@ -17,11 +17,13 @@ config.substitutions.append(
     )
 )
 
+sed_cmd = "/opt/freeware/bin/sed" if "system-aix" in config.available_features else "sed"
+
 # Filtering command for testing SARIF output against reference output.
 config.substitutions.append(
     (
         "%normalize_sarif",
-        "sed -r '%s;%s;%s;%s'"
+        f"{sed_cmd} -r '%s;%s;%s;%s'"
         % (
             # Replace version strings that are likely to change.
             r's/"version": ".* version .*"/"version": "[clang version]"/',