Fix type forwarding for init and record workaround

Author: andyleejordan

src/JsonRpc.Generators/Records.cs

@@ -1,6 +1,8 @@
 #pragma warning disable MA0048 // File name must match type name
-#define INTERNAL_RECORD_ATTRIBUTES
-#if NETSTANDARD2_0 ||  NETSTANDARD2_1 ||  NETCOREAPP2_0 ||  NETCOREAPP2_1 ||  NETCOREAPP2_2 || NET45 || NET451 || NET452 || NET6 || NET461 || NET462 || NET47 || NET471 || NET472 || NET48
+#if NET5_0_OR_GREATER
+[assembly: System.Runtime.CompilerServices.TypeForwardedTo(typeof(System.Runtime.CompilerServices.IsExternalInit))]
+#else
+
 using System.ComponentModel;
 
 // ReSharper disable once CheckNamespace
@@ -11,12 +13,7 @@ namespace System.Runtime.CompilerServices
     /// This class should not be used by developers in source code.
     /// </summary>
     [EditorBrowsable(EditorBrowsableState.Never)]
-#if INTERNAL_RECORD_ATTRIBUTES
-    internal
-#else
-    public
-#endif
-        static class IsExternalInit
+    internal static class IsExternalInit
     {
     }
 }

src/JsonRpc/Nullable/Records.cs

@@ -1,6 +1,8 @@
 #pragma warning disable MA0048 // File name must match type name
-#define INTERNAL_RECORD_ATTRIBUTES
-#if NETSTANDARD || NETCOREAPP
+#if NET5_0_OR_GREATER
+[assembly: System.Runtime.CompilerServices.TypeForwardedTo(typeof(System.Runtime.CompilerServices.IsExternalInit))]
+#else
+
 using System.ComponentModel;
 
 // ReSharper disable once CheckNamespace
@@ -11,12 +13,7 @@ namespace System.Runtime.CompilerServices
     /// This class should not be used by developers in source code.
     /// </summary>
     [EditorBrowsable(EditorBrowsableState.Never)]
-#if INTERNAL_RECORD_ATTRIBUTES
-    internal
-#else
-    public
-#endif
-        static class IsExternalInit
+    internal static class IsExternalInit
     {
     }
 }