Assertion failure on getStack with a BoundVariable of type @TypeArguments

[DanTup]

I hit this failed assertion in getStack. It's expecting the type of a BoundVariable to be @Instance or Instance but it's a @TypeArguments:

Here's the problematic JSON:

{
	"type": "BoundVariable",
	"name": "function_type_arguments_var",
	"value": {
		"type": "@TypeArguments",
		"class": {
			"type": "@Class",
			"fixedId": true,
			"id": "classes\/41",
			"name": "TypeArguments"
		},
		"id": "objects\/137",
		"name": "<FutureOr<dynamic>, bool>"
	},
	"declarationTokenPos": -1,
	"scopeStartTokenPos": -1,
	"scopeEndTokenPos": 50428
}

And here is the full stack response from the VM.

[DanTup]

The code I'm stepping through looks like this:

Future<void> doAsyncStuff() async {
    print("test"); // BREAKPOINT
    await new Future.value(true);
    print("test2");
    await new Future.microtask(() => true);
    print("test3");
    await new Future.delayed(const Duration(milliseconds: 1));
    print("done!");
  }

[devoncarew]

For context, this is blocking us from writing some tests we'd like to have for Flutter.

[devoncarew]

I think for this case, the spec needs to be updated:

class BoundVariable {
  /// [value] can be one of [InstanceRef] or [Sentinel].
  dynamic value;

For above, we should add TypeArguments, or instead reference the parent type, ObjRef.

and, the assert should be updated to allow for TypeArgumentsRef.

[DanTup]

I've opened a PR that updates the spec. Once that's resolved (assuming it's correct) I'll take a look at this - looks like we already have a newVMTypeArgumentsRef so possibly we can handle this in the caller of the function in the first screenshot (which is newVMInstanceRefOrSentinel, but maybe should be renamed with this change).