Fixed the generated C# for pure virtual functions with default arguments.

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

src/Generator/Driver.cs

@@ -251,12 +251,12 @@ namespace CppSharp
 
             if (Options.IsCSharpGenerator)
             {
-                TranslationUnitPasses.AddPass(new GenerateAbstractImplementationsPass());
                 if (Options.GenerateDefaultValuesForArguments)
                 {
                     TranslationUnitPasses.AddPass(new FixDefaultParamValuesOfOverridesPass());
                     TranslationUnitPasses.AddPass(new HandleDefaultParamValuesPass());
                 }
+                TranslationUnitPasses.AddPass(new GenerateAbstractImplementationsPass());
                 TranslationUnitPasses.AddPass(new MultipleInheritancePass());
             }
             TranslationUnitPasses.AddPass(new DelegatesPass());

src/Generator/Passes/GenerateAbstractImplementationsPass.cs

@@ -64,7 +64,8 @@ namespace CppSharp.Passes
                         Namespace = internalImpl,
                         OriginalFunction = abstractMethod,
                         IsPure = false,
-                        SynthKind = FunctionSynthKind.AbstractImplCall
+                        SynthKind = abstractMethod.SynthKind == FunctionSynthKind.DefaultValueOverload ?
+                            FunctionSynthKind.DefaultValueOverload : FunctionSynthKind.AbstractImplCall
                     };
                 impl.OverriddenMethods.Clear();
                 impl.OverriddenMethods.Add(abstractMethod);

tests/CSharp/CSharp.h

@@ -444,6 +444,12 @@ private:
     Foo m_foo;
 };
 
+class DLL_API HasPureVirtualWithDefaultArg
+{
+public:
+    virtual void pureVirtualWithDefaultArg(Foo* foo = nullptr) = 0;
+};
+
 class DLL_API HasOverridesWithChangedAccessBase
 {
 public: