Add missing include guard in header file. (#20635)

diff --git a/src/vm/callsiteinspect.h b/src/vm/callsiteinspect.h
index 8a2d7cc..df7b900 100644 (file)
--- a/src/vm/callsiteinspect.h
+++ b/src/vm/callsiteinspect.h
@@ -2,6 +2,8 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#pragma once
+
 struct CallsiteDetails
 {
     // The signature of the current call