Enable MiniJSON test for MCS 2.6.4

ICSharpCode.Decompiler.Tests/CorrectnessTestRunner.cs

@@ -1,4 +1,4 @@
-// Copyright (c) AlphaSierraPapa for the SharpDevelop Team
+// Copyright (c) AlphaSierraPapa for the SharpDevelop Team
 // 
 // Permission is hereby granted, free of charge, to any person obtaining a copy of this
 // software and associated documentation files (the "Software"), to deal in the Software
@@ -398,10 +398,6 @@ namespace ICSharpCode.Decompiler.Tests
 		[Test]
 		public async Task MiniJSON([ValueSource(nameof(defaultOptions))] CompilerOptions options)
 		{
-			if (options.HasFlag(CompilerOptions.UseMcs2_6_4))
-			{
-				Assert.Ignore("Decompiler bug with mono!");
-			}
 			await RunCS(options: options);
 		}