Added support for function to instance method conversions in the CLI generator.

This boils down to ignoring the first argument when we are generating the method parameters and calling NativePtr when we need access to the first argument.

src/Generator/Generators/CLI/CLIHelpers.cs

@@ -438,6 +438,10 @@ namespace Cxxi.Generators.CLI
         {
             for (var i = 0; i < method.Parameters.Count; ++i)
             {
+                if (method.Conversion == MethodConversionType.FunctionToInstanceMethod
+                    && i == 0)
+                    continue;
+
                 var param = method.Parameters[i];
                 Write("{0}", TypeSig.GetArgumentString(param));
                 if (i < method.Parameters.Count - 1)

src/Generator/Generators/CLI/CLIMarshal.cs

@@ -436,6 +436,15 @@ namespace Cxxi.Generators.CLI
                 if (!Context.Parameter.Type.IsPointer())
                     Return.Write("*");
 
+                var method = Context.Function as Method;
+                if (method != null
+                    && method.Conversion == MethodConversionType.FunctionToInstanceMethod
+                    && Context.ParameterIndex == 0)
+                {
+                    Return.Write("NativePtr");
+                    return true;
+                }
+
                 Return.Write("{0}->NativePtr", Context.Parameter.Name);
             }