Added int128 and uint128 to the marshalling structures in the C# generator. (#858)

fixed #771

src/Generator/Generators/CSharp/CSharpSources.cs

@@ -615,10 +615,6 @@ namespace CppSharp.Generators.CSharp
             var coreType = field.QualifiedType.Type.Desugar();
             if (arrayType != null && arrayType.SizeType == ArrayType.ArraySize.Constant)
                 coreType = arrayType.Type.Desugar();
-            // we do not support the primitives below yet because their representation in C# is problematic
-            if (coreType.IsPrimitiveType(PrimitiveType.Int128) ||
-                coreType.IsPrimitiveType(PrimitiveType.UInt128))
-                return;
 
             TypePrinterResult retType = TypePrinter.VisitFieldDecl(
                 new Field { Name = field.Name, QualifiedType = field.QualifiedType });

src/Generator/Generators/CSharp/CSharpTypePrinter.cs

@@ -512,8 +512,10 @@ namespace CppSharp.Generators.CSharp
                 case PrimitiveType.LongLong:
                 case PrimitiveType.ULongLong:
                     return GetIntString(primitive, Context.TargetInfo);
-                case PrimitiveType.Int128: return "__int128";
-                case PrimitiveType.UInt128: return "__uint128_t";
+                case PrimitiveType.Int128: return new TypePrinterResult { Type = "fixed byte",
+                    NameSuffix = "[16]"}; // The type is always 128 bits wide
+                case PrimitiveType.UInt128: return new TypePrinterResult { Type = "fixed byte",
+                    NameSuffix = "[16]"}; // The type is always 128 bits wide
                 case PrimitiveType.Half: return new TypePrinterResult { Type = "fixed byte",
                     NameSuffix = $"[{Context.TargetInfo.HalfWidth}]"};
                 case PrimitiveType.Float: return "float";