UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3202.75 Safari/537.36

Steps to reproduce the problem:
In devtools, run e.g.:

new Set([1]).entries()

What is the expected behavior?
The output should be an array with the value contained as first and second entry.

What went wrong?
By spec, the result should be `SetIterator { [1, 1] }`. Instead, it's `SetIterator { 1 }`. Iterator entries should always return an array. This is the case to align the behavior with map entries.

Did this work before? No 

Chrome version: 71.0.3202.75  Channel: stable
OS Version: 
Flash Version: 

This is an issue in V8 and I opened a fix for this already: https://chromium-review.googlesource.com/c/v8/v8/+/1350790

However, two blink layout tests fail and I intend to set the test expectation to allow them to fail, so the patch may land.

Afterwards I'll go ahead and fix the layout test itself as well.