Hack to silently ignore non-class base class (e.g. templates etc)

src/AST/Class.cs

@@ -213,7 +213,7 @@ namespace CppSharp.AST
         public Method GetRootBaseMethod(Method @override, bool onlyFirstBase = false)
         {
             return (from @base in Bases
-                    where !onlyFirstBase || !@base.Class.IsInterface
+                    where @base.IsClass && (!onlyFirstBase || !@base.Class.IsInterface)
                     let baseMethod = (
                         from method in @base.Class.Methods
                         where

src/Generator/Generators/CSharp/CSharpTextTemplate.cs

@@ -716,6 +716,7 @@ namespace CppSharp.Generators.CSharp
             {
                 bases.AddRange(
                     from @base in @class.Bases
+                    where @base.IsClass
                     select QualifiedIdentifier(@base.Class));
             }