Added C#-printing of float128.

Signed-off-by: Dimitar Dobrev <dpldobrev@protonmail.com>

src/Generator/Generators/CSharp/CSharpTypePrinter.cs

@@ -526,6 +526,7 @@ namespace CppSharp.Generators.CSharp
                 case PrimitiveType.UIntPtr: return "global::System.UIntPtr";
                 case PrimitiveType.Null: return "void*";
                 case PrimitiveType.String: return "string";
+                case PrimitiveType.Float128: return "__float128";
             }
 
             throw new NotSupportedException();