Added the deltablue benchmark.
Created originally on Bitbucket by toastdriven (Daniel Lindsley)
Was already merged in Bitbucket before import, marked as merged by the import user
Per @fijal 's tweet (https://twitter.com/fijall/status/372008783435677696), here's a ported version of V8's DeltaBlue. Apologies if I borked the pull request or the integration with the benchmark harnass.
As for the port itself, I'm somewhat confident. Unfortunately, AFAICT, the benchmark itself doesn't exercise all the code, so I'm hoping no one tries to use it in production. The code is ugly but I tried to remain as close to the original as possible.
Please let me know if there's anything else I can add/change to make the PR more palatable.