Fixed the wrapping of functions taking a function pointer.

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

src/Generator/Generators/CSharp/CSharpTypePrinter.cs

@@ -120,6 +120,9 @@ namespace CppSharp.Generators.CSharp
             if (arguments.Count > 0)
                 args = VisitParameters(function.Parameters, hasNames: false).Type;
 
+            if (ContextKind != CSharpTypePrinterContextKind.Managed)
+                return "global::System.IntPtr";
+
             if (returnType.Type.IsPrimitiveType(PrimitiveType.Void))
             {
                 if (!string.IsNullOrEmpty(args))

tests/Basic/Basic.cpp

@@ -71,7 +71,7 @@ int Hello::RetEnum(Enum e)
     return (int)e;
 }
 
-int unsafeFunction(const Bar& ret, char* testForString)
+int unsafeFunction(const Bar& ret, char* testForString, void (*foo)(int))
 {
     return ret.A;
 }

tests/Basic/Basic.h

@@ -73,4 +73,4 @@ public:
 
 DLL_API Bar operator+(const Bar &, const Bar &);
 
-int DLL_API unsafeFunction(const Bar& ret, char* testForString);
+int DLL_API unsafeFunction(const Bar& ret, char* testForString, void (*foo)(int));