[TypeSystem] Specialized method now contains a flag specifying the

extension method mode.
There needs some distinction between extension methods calles foo.Ext
(); and Class.Ext(foo); even if it's the same method call - it's
different for code completion tooltips.

ICSharpCode.NRefactory.CSharp/Resolver/OverloadResolution.cs

@@ -950,6 +950,8 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 			if (member == null)
 				throw new InvalidOperationException();
 			
+			if (this.IsExtensionMethodInvocation)
+				((SpecializedMethod)member).IsExtendedExtensionMethod = true;
 			return new CSharpInvocationResolveResult(
 				this.IsExtensionMethodInvocation ? new TypeResolveResult(member.DeclaringType) : targetResolveResult,
 				member,

ICSharpCode.NRefactory/TypeSystem/Implementation/SpecializedMethod.cs

@@ -153,6 +153,14 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 				accessorOwner = value;
 			}
 		}
+
+		/// <summary>
+		/// Gets/Sets whether the method is an extension method that are being called using extension method syntax.
+		/// </summary>
+		public bool IsExtendedExtensionMethod {
+			get;
+			set;
+		}
 		
 		public override IMemberReference ToMemberReference()
 		{