Check for constness first in CheckAmbiguousFunctionPass before doing the check for default parameters.

Fixes test case from previous commit.

src/Generator/Passes/CheckAmbiguousFunctions.cs

@@ -44,10 +44,10 @@ namespace CppSharp.Passes
 
                 if (!overload.IsGenerated) continue;
 
-                if (!CheckDefaultParameters(function, overload))
+                if (!CheckConstness(function, overload))
                     continue;
 
-                if (!CheckConstness(function, overload))
+                if (!CheckDefaultParameters(function, overload))
                     continue;
 
                 function.IsAmbiguous = true;