Translating these idioms to "*data = 0" was one of the first peephole optimizations I implemented when writing my own optimizing brainfuck interpreter.
I'm excited to hear about how you intend to solve input instructions. I've been struggling with that myself since I want to make it asynchronous, which might require some nasty tricks.
I realized after coding that first version that most brainfuck programs run indefinitely. Apart from Hello World, I didn't find lots of program I could run synchronously. Making it asynchronous sounds like a tough job.
To be fair I don't think this announcement ever spread that far and I don't think it was ever announced that the validation would be enabled in Chrome, nevertheless I see asm.js validation messages (or rather, invalidation messages when there's issues) in Chrome 64.
