Reimplement APM UDP Socket methods on top of task variants and consolidate related tests

src/libraries/System.Net.Sockets/src/System.Net.Sockets.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)</TargetFrameworks>
@@ -46,8 +46,6 @@
     <Compile Include="System\Net\Sockets\AcceptOverlappedAsyncResult.cs" />
     <Compile Include="System\Net\Sockets\BaseOverlappedAsyncResult.cs" />
     <Compile Include="System\Net\Sockets\DisconnectOverlappedAsyncResult.cs" />
-    <Compile Include="System\Net\Sockets\OverlappedAsyncResult.cs" />
-    <Compile Include="System\Net\Sockets\ReceiveMessageOverlappedAsyncResult.cs" />
     <Compile Include="System\Net\Sockets\UnixDomainSocketEndPoint.cs" />
     <!-- Logging -->
     <Compile Include="$(CommonPath)System\Net\Logging\NetEventSource.Common.cs"
@@ -94,9 +92,7 @@
     <!-- Windows: CoreCLR -->
     <Compile Include="System\Net\Sockets\AcceptOverlappedAsyncResult.Windows.cs" />
     <Compile Include="System\Net\Sockets\BaseOverlappedAsyncResult.Windows.cs" />
-    <Compile Include="System\Net\Sockets\OverlappedAsyncResult.Windows.cs" />
     <Compile Include="System\Net\Sockets\DynamicWinsockMethods.cs" />
-    <Compile Include="System\Net\Sockets\ReceiveMessageOverlappedAsyncResult.Windows.cs" />
     <Compile Include="System\Net\Sockets\SafeSocketHandle.Windows.cs" />
     <Compile Include="System\Net\Sockets\Socket.Windows.cs" />
     <Compile Include="System\Net\Sockets\SocketAsyncEventArgs.Windows.cs" />
@@ -192,8 +188,6 @@
     <Compile Include="System\Net\Sockets\AcceptOverlappedAsyncResult.Unix.cs" />
     <Compile Include="System\Net\Sockets\BaseOverlappedAsyncResult.Unix.cs" />
     <Compile Include="System\Net\Sockets\DisconnectOverlappedAsyncResult.Unix.cs" />
-    <Compile Include="System\Net\Sockets\OverlappedAsyncResult.Unix.cs" />
-    <Compile Include="System\Net\Sockets\ReceiveMessageOverlappedAsyncResult.Unix.cs" />
     <Compile Include="System\Net\Sockets\SafeSocketHandle.Unix.cs" />
     <Compile Include="System\Net\Sockets\Socket.Unix.cs" />
     <Compile Include="System\Net\Sockets\SocketAsyncContext.Unix.cs" />

src/libraries/System.Net.Sockets/src/System/Net/Sockets/BaseOverlappedAsyncResult.cs

@@ -21,12 +21,5 @@ internal partial class BaseOverlappedAsyncResult : ContextAwareResult
             _numBytes = numBytes;
             return s_resultObjectSentinel; // return sentinel rather than boxing numBytes
         }
-
-        // Used instead of the base InternalWaitForCompletion when storing an Int32 result
-        internal int InternalWaitForCompletionInt32Result()
-        {
-            base.InternalWaitForCompletion();
-            return _numBytes;
-        }
     }
 }