Bug 155153

function foo() { let arr = () => { if (false) { print(new.target); } else { print(new.target); } }; arr(); } new foo(); This prints undefined. It shouldn't. The reason is that we make a classic mistake where we emit code to load new.target once. Even if that code is behind a branch in byte code, we assume all uses can use that already loaded value. That's wrong. We either need to always emit the load from the scope for each new.target, or we need to emit the load at the function prologue before any uses of new.target. I think loading it from the scope is probably cleaner because the alternative punishes programs that never use new.target. That said, always loading it from the scope will punish programs that do the load in a loop.