Scale back [Serializable] CoreFX types (dotnet#19742)

* Remove SerializableAttribute from many CoreFX types that will not be serializable.

* Removes serialization tests for types that are no longer serializable and fixes serializing a couple of types. Includes marking some internal serializable types as public so that they'll be reflectible with .NET Native.

* Remove unneeded pragmas

* Update based on review comments

Author: morganbr

CodeAnalysis.ruleset

@@ -19,7 +19,7 @@
     <Rule Id="CA2229" Action="Error" /> <!-- Serializable type doesn't have a serialization constructor -->
     <Rule Id="CA2235" Action="None" /> <!-- Serializable type has non serializable field -->
     <Rule Id="CA2231" Action="None" /> <!-- Overload operator equals when overriding ValueType.Equals -->
-    <Rule Id="CA2237" Action="Error" /> <!-- Add [Serializable] to types that implement ISerializable -->
+    <Rule Id="CA2237" Action="None" /> <!-- Add [Serializable] to types that implement ISerializable -->
 
     <Rule Id="CA2200" Action="None"/> <!-- Rethrowing caught exception changes stack information -->
 

src/Common/src/System/CodeDom/CodeObject.cs

@@ -11,7 +11,6 @@ namespace System.CodeDom
 namespace System.Runtime.Serialization
 #endif
 {
-    [Serializable]
 #if !FEATURE_SERIALIZATION
     public class CodeObject
 #else

src/Common/src/System/CodeDom/CodeTypeReference.cs

@@ -23,7 +23,6 @@ internal enum CodeTypeReferenceOptions
         GenericTypeParameter = 0x00000002
     }
 
-    [Serializable]
 #if !FEATURE_SERIALIZATION
     public class CodeTypeReference : CodeObject
 #else

src/Common/src/System/CodeDom/CodeTypeReferenceCollection.cs

@@ -10,7 +10,6 @@ namespace System.CodeDom
 namespace System.Runtime.Serialization
 #endif
 {
-    [Serializable]
 #if !FEATURE_SERIALIZATION
     public class CodeTypeReferenceCollection : CollectionBase
 #else

src/Common/src/System/Collections/CompatibleComparer.cs

@@ -6,7 +6,6 @@
 
 namespace System.Collections
 {
-    [Serializable]
     internal sealed class CompatibleComparer : IEqualityComparer
     {
         private readonly IHashCodeProvider _hcp;

src/Common/src/System/Data/Common/NameValuePair.cs

@@ -7,7 +7,6 @@
 
 namespace System.Data.Common
 {
-    [Serializable]
     internal sealed class NameValuePair
     {
         readonly private string _name;

src/Common/src/System/Net/NetworkInformation/NetworkInformationException.cs

@@ -14,7 +14,6 @@ namespace System.Net.NetworkInformation
     ///       Provides NetworkInformation exceptions to the application.
     ///    </para>
     /// </devdoc>
-    [Serializable]
     public class NetworkInformationException : Win32Exception
     {
         /// <devdoc>

src/Common/src/System/Text/DBCSDecoder.cs

@@ -8,7 +8,6 @@
 
 namespace System.Text
 {
-    [Serializable]
     internal sealed class DecoderDBCS : Decoder
     {
         private readonly Encoding _encoding;

src/Common/src/System/Text/OSEncoder.cs

@@ -8,7 +8,6 @@
 
 namespace System.Text
 {
-    [Serializable]
     internal sealed class OSEncoder : Encoder
     {
         private char _charLeftOver;

src/Common/src/System/Text/OSEncoding.Windows.cs

@@ -9,7 +9,6 @@
 
 namespace System.Text
 {
-    [Serializable]
     internal sealed class OSEncoding : Encoding
     {
         private readonly int _codePage;