Add preprocessor directive

Author: ds5678

ICSharpCode.Decompiler.Tests/TestCases/Pretty/CompoundAssignmentTest.cs

@@ -4947,18 +4947,20 @@ public void Issue1779(int value)
 			customStruct.IntProp += value;
 		}
 
-		public static string PreincrementWithMethodCall(int value)
+#if ROSLYN2
+		public static string PreIncrementWithMethodCall(int value)
 		{
 			return (++value).ToString();
 		}
+#endif
 
 #if CS72
-		public static string PreincrementWithInParameter(int value)
+		public static string PreIncrementWithInParameter(int value)
 		{
-			PreincrementWithInParameter_Helper(++value);
+			PreIncrementWithInParameter_Helper(++value);
 			return value.ToString();
 		}
-		public static void PreincrementWithInParameter_Helper(in int value)
+		public static void PreIncrementWithInParameter_Helper(in int value)
 		{
 		}
 #endif