From ae7f9c226649a332447d773510ea9e0aa484520a Mon Sep 17 00:00:00 2001
From: Ian Anderson <iana@apple.com>
Date: Tue, 3 Jun 2025 17:23:44 -0700
Subject: [PATCH] [Option] Add a feature flag for -Isystem

swift-build needs a flag to know if -Isystem is available.

rdar://152540225
---
 lib/Option/features.json | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/Option/features.json b/lib/Option/features.json
index 4bef4b444b0d5..f9c87c00022b9 100644
--- a/lib/Option/features.json
+++ b/lib/Option/features.json
@@ -47,6 +47,9 @@
     },
     {
        "name": "experimental-package-interface-load"
+    },
+    {
+       "name": "Isystem"
     }
   ]
 }