Relax RegisterForAot classes so they're accessible in PCL arch dlls

Author: mythz

src/ServiceStack.Text/Common/JsReader.cs

@@ -5,7 +5,7 @@
 
 namespace ServiceStack.Text.Common
 {
-    internal class JsReader<TSerializer>
+    public class JsReader<TSerializer>
         where TSerializer : ITypeSerializer
     {
         private static readonly ITypeSerializer Serializer = JsWriter.GetTypeSerializer<TSerializer>();

src/ServiceStack.Text/Common/JsWriter.cs

@@ -151,7 +151,7 @@ public static void WriteEnumFlags(TextWriter writer, object enumFlagValue)
         }
     }
 
-    internal class JsWriter<TSerializer>
+    public class JsWriter<TSerializer>
         where TSerializer : ITypeSerializer
     {
         private static readonly ITypeSerializer Serializer = JsWriter.GetTypeSerializer<TSerializer>();

src/ServiceStack.Text/Jsv/JsvTypeSerializer.cs

@@ -9,7 +9,7 @@
 
 namespace ServiceStack.Text.Jsv
 {
-	internal class JsvTypeSerializer
+    public class JsvTypeSerializer
 		: ITypeSerializer
 	{
 		public static ITypeSerializer Instance = new JsvTypeSerializer();