Add back argument check for TypeForwardedFromAttribute (#16680)

Fixes dotnet/corefx#27554

diff --git a/src/mscorlib/shared/System/Runtime/CompilerServices/TypeForwardedFromAttribute.cs b/src/mscorlib/shared/System/Runtime/CompilerServices/TypeForwardedFromAttribute.cs
index c4a8558..27dd645 100644 (file)
--- a/src/mscorlib/shared/System/Runtime/CompilerServices/TypeForwardedFromAttribute.cs
+++ b/src/mscorlib/shared/System/Runtime/CompilerServices/TypeForwardedFromAttribute.cs
@@ -9,6 +9,9 @@ namespace System.Runtime.CompilerServices
     {
         public TypeForwardedFromAttribute(string assemblyFullName)
         {
+            if (string.IsNullOrEmpty(assemblyFullName))
+                throw new ArgumentNullException(nameof(assemblyFullName));
+
             AssemblyFullName = assemblyFullName;
         }