No I don’t think Google is on the forefront of that type of thing. It’s more of a practical craft. There may be people doing interesting PL research at Google but they aren’t in the language platform team. That said these are probably some of the tightest, safest, and best-tested large-scale C++ programs ever.
Agree with the scale. But do you mean the compilers toolchain is the largest/safest; or the overall C++ codebase. No questions about the latter, but would be surprised if you meant the former.
Out of curiosity: if not the language platform team, then which team does PL research? My email is in my profile of you'd rather ping there.
I would have definitely said yes back in the day; but not so sure now.
(Admittedly might be biased. I'm the founder of Synthetic Minds. We're building program synthesizers; basically all compilers work: https://news.ycombinator.com/item?id=19059922)