Well, sure, but a big chunk of the bugs in JRE were in the library, not the code generation or GC.
Speaking of: Neon, a system for writing Node libraries in Rust is pretty cool:
Not sure exactly how much it buys you but I suspect there’s still room for research especially since Mozilla themselves has interest in a Rust JS JIT. I am curious to see if HolyJIT goes anywhere and what kinds of safety improvements it could potentially offer.
That said, a rust JS runtime would be amazing just because it's easier to integrate into rust projects.