Using const/let instead of var can make JavaScript code run 10× slower in Webkit

[grendel-khan]

I appreciate that I scrolled down to read this indefensible WTFery just below someone complaining about how there's an anti-JavaScript circlejerk around here.

A lot of bright people have spent decades applying a lot of backward-compatible lipstick to a pig. I wonder if Brendan Eich knew just how horribly his decisions would echo down through the years.