Added enum to keep different type and declaration conversion kinds.

src/Bridge/Conversions.cs

@@ -0,0 +1,16 @@
+namespace Cxxi
+{
+    public enum TypeConversionKind
+    {
+        None,
+        RawPtrToIntPtr,
+        ConstCharPtrToString,
+    }
+
+    public enum MethodConversionKind
+    {
+        None,
+        FunctionToInstanceMethod,
+        FunctionToStaticMethod
+    }
+}