Revert "[TypeSystem] Specialized method now contains a flag specifying the"

This reverts commit bd1811cc18.

Conflicts:
	ICSharpCode.NRefactory.CSharp/Resolver/OverloadResolution.cs

ICSharpCode.NRefactory.CSharp/Resolver/OverloadResolution.cs

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

ICSharpCode.NRefactory/TypeSystem/Implementation/SpecializedMethod.cs

@@ -153,14 +153,6 @@ 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()
 		{