Added some changes to work around mcs bugs.

ICSharpCode.NRefactory/CSharp/Resolver/CSharpResolver.cs

@@ -70,8 +70,8 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 		
 		class OperatorMethod : Immutable, IParameterizedMember
 		{
-			static readonly IParameter[] normalParameters = new IParameter[TypeCode.String + 1 - TypeCode.Object];
-			static readonly IParameter[] nullableParameters = new IParameter[TypeCode.Decimal + 1 - TypeCode.Boolean];
+			static readonly IParameter[] normalParameters = new IParameter[(int)(TypeCode.String + 1 - TypeCode.Object)];
+			static readonly IParameter[] nullableParameters = new IParameter[(int)(TypeCode.Decimal + 1 - TypeCode.Boolean)];
 			
 			static OperatorMethod()
 			{

ICSharpCode.NRefactory/CSharp/Resolver/OverloadResolution.cs

@@ -335,7 +335,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 		{
 			bool c1IsBetter = false;
 			bool c2IsBetter = false;
-			foreach (var pair in t1.Zip(t2, Tuple.Create)) {
+			foreach (var pair in t1.Zip<IType, IType, Tuple<IType, IType>>(t2, Tuple.Create)) {
 				switch (MoreSpecificFormalParameter(pair.Item1, pair.Item2)) {
 					case 1:
 						c1IsBetter = true;