JS engine detection with tail recursion

```JS
function detect(){
  "use strict" //necessary for Safari to eliminate tail calls
  function recurse(N) {if (N ===0) return "JavaScriptCore"; else return recurse(N-1)}
  try {return recurse(2**16)} catch(e) {
    if (e instanceof RangeError) return "V8"
    else return "SpiderMonkey" // here, `e instanceof InternalError` is true
  }
}
detect()
```
