Added 'UnknownTypeResolveResult'.

Makes it easier to implement the 'add missing namespace import'
function.

ICSharpCode.NRefactory.CSharp/Resolver/CSharpResolver.cs

@@ -2062,7 +2062,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 				else
 					return new UnknownIdentifierResolveResult(identifier);
 			} else {
-				return ErrorResult;
+				return new UnknownTypeResolveResult(identifier, typeArguments.Count);
 			}
 		}
 		

ICSharpCode.NRefactory/ICSharpCode.NRefactory.csproj

@@ -194,6 +194,7 @@
     <Compile Include="Completion\CompletionCategory.cs" />
     <Compile Include="Completion\IParameterDataProvider.cs" />
     <Compile Include="Completion\IVariableCompletionData.cs" />
+    <Compile Include="Semantics\UnknownTypeResolveResult.cs" />
   </ItemGroup>
   <ItemGroup>
     <Folder Include="Completion\" />

ICSharpCode.NRefactory/Semantics/UnknownTypeResolveResult.cs

@@ -0,0 +1,67 @@
+// 
+// UnknownTypeResolveResult.cs
+//  
+// Author:
+//       Mike Krüger <mkrueger@xamarin.com>
+// 
+// Copyright (c) 2011 Xamarin Inc. (http://xamarin.com)
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using ICSharpCode.NRefactory.TypeSystem;
+
+namespace ICSharpCode.NRefactory.Semantics
+{
+	/// <summary>
+	/// Represents an unknown type with type parameters.
+	/// </summary>
+	public class UnknownTypeResolveResult : ResolveResult
+	{
+		readonly string identifier;
+		readonly int typeParameterCount;
+		
+		public UnknownTypeResolveResult(string identifier, int typeParameterCount)
+			: base(SharedTypes.UnknownType)
+		{
+			this.identifier = identifier;
+			this.typeParameterCount = typeParameterCount;
+		}
+		
+		public string Identifier {
+			get { return identifier; }
+		}
+
+		public int TypeParameterCount {
+			get { return typeParameterCount; }
+		}
+		
+		public override bool IsError {
+			get { return true; }
+		}
+		
+		public override string ToString()
+		{
+			return string.Format("[{0} {1}~{2}]", GetType().Name, identifier, typeParameterCount);
+		}
+	}
+}