Add back using to EventSourceException

Signed-off-by: dotnet-bot <dotnet-bot@microsoft.com>
Commit migrated from https://github.com/dotnet/coreclr/commit/0d427ca705cb7a23aa5d4902b5e19f679c7b322e

diff --git a/src/libraries/System.Private.CoreLib/src/System/Diagnostics/Tracing/EventSourceException.cs b/src/libraries/System.Private.CoreLib/src/System/Diagnostics/Tracing/EventSourceException.cs
index 2e821ac..f5f9ba1 100644 (file)
--- a/src/libraries/System.Private.CoreLib/src/System/Diagnostics/Tracing/EventSourceException.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Diagnostics/Tracing/EventSourceException.cs
@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 #nullable enable
+using System;
 using System.Runtime.Serialization;
 
 #if ES_BUILD_STANDALONE