CSharpExpressionPrinter: Wrap expression in parenthesis

Wrap default parameter expressions in parentheses to ensure whole expressions are casted instead of only the first operand.

src/Generator/Generators/CSharp/CSharpExpressionPrinter.cs

@@ -27,11 +27,11 @@ namespace CppSharp.Generators.CSharp
             if (desugared.IsPrimitiveType() &&
                 (parameter.DefaultArgument.Declaration != null ||
                  parameter.DefaultArgument.Class == StatementClass.BinaryOperator))
-                return $"({desugared.Visit(typePrinter)}) {expression}";
+                return $"({desugared.Visit(typePrinter)}) ({expression})";
             var finalType = (desugared.GetFinalPointee() ?? desugared).Desugar();
             if (finalType.TryGetClass(out var @class) && @class.IsInterface)
                 return $@"({@class.Visit(typePrinter)}) ({
-                    @class.OriginalClass.Visit(typePrinter)}) {expression}";
+                    @class.OriginalClass.Visit(typePrinter)}) ({expression})";
             return expression;
         }
 

tests/dotnet/Common/Common.cpp

@@ -1274,3 +1274,7 @@ extern "C"
         return s;
     }
 } // extern "C"
+
+void DLL_API FunctionWithFlagsAsDefaultParameter(int defaultParam)
+{
+}

tests/dotnet/Common/Common.h

@@ -1567,3 +1567,5 @@ extern "C"
     DLL_API void takeConflictName(struct system* self);
     DLL_API struct system freeFunctionReturnByValue();
 } // extern "C"
+
+void DLL_API FunctionWithFlagsAsDefaultParameter(int defaultParam = A | B);