It returns true if the child is a GetLocal and the local's prediction is PredictString. But that's not right, since PredictString just means that the local is predicted to be a string, rather than it's known to be a string.
For some predictions, like array, boolean, and int32, we enforce predictions on local variables when we do a SetLocal. But we don't do this for strings. Hence, we can't have the same logic for strings as we have for those types.
Created attachment 109915 [details]
Comment on attachment 109915 [details]
It makes me sad that we can't propagate stringiness :-(
(In reply to comment #2)
> (From update of attachment 109915 [details])
> It makes me sad that we can't propagate stringiness :-(
I'm working on it! Happy thoughts!
Landed in r96794.