Fix build.

ICSharpCode.Decompiler/CSharp/Transforms/AddXmlDocumentationTransform.cs

@@ -20,6 +20,7 @@ using System;
 using System.IO;
 using System.Linq;
 using ICSharpCode.Decompiler.CSharp.Syntax;
+using ICSharpCode.Decompiler.Documentation;
 using ICSharpCode.Decompiler.TypeSystem;
 
 namespace ICSharpCode.Decompiler.CSharp.Transforms

ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj

@@ -253,7 +253,7 @@
     <Compile Include="CSharp\Transforms\IntroduceUnsafeModifier.cs" />
     <Compile Include="CSharp\Transforms\ReplaceMethodCallsWithOperators.cs" />
     <Compile Include="CSharp\WholeProjectDecompiler.cs" />
-    <Compile Include="Documentation\AddXmlDocumentationTransform.cs" />
+    <Compile Include="CSharp\Transforms\AddXmlDocumentationTransform.cs" />
     <Compile Include="Documentation\GetPotentiallyNestedClassTypeReference.cs" />
     <Compile Include="Documentation\IdStringMemberReference.cs" />
     <Compile Include="Documentation\IdStringProvider.cs" />