Fix ProjectN regression in `ByReference<T>` (dotnet/corert#6713)

Signed-off-by: dotnet-bot <dotnet-bot@microsoft.com>

diff --git a/src/System.Private.CoreLib/shared/System/ByReference.cs b/src/System.Private.CoreLib/shared/System/ByReference.cs
index 492979a..5da3c99 100644 (file)
--- a/src/System.Private.CoreLib/shared/System/ByReference.cs
+++ b/src/System.Private.CoreLib/shared/System/ByReference.cs
@@ -11,7 +11,11 @@ namespace System
     // around lack of first class support for byref fields in C# and IL. The JIT and 
     // type loader has special handling for it that turns it into a thin wrapper around ref T.
     [NonVersionable]
-    internal readonly ref struct ByReference<T>
+    internal
+#if !PROJECTN // readonly breaks codegen contract and asserts UTC
+    readonly
+#endif
+    ref struct ByReference<T>
     {
         // CS0169: The private field '{blah}' is never used
 #pragma warning disable 169