I'm happy to see this moment. I don't want to diminish it, but aren't these tools written in a "tasteful subset" of c++, which could mean there are still many missing nooks and crannies?
Yup, which is why self hosting is a step (albeit a very cool one) on the way. You still have to deal with all the features and idioms you don't know - I remember Duff's device and other forms of switch abuse falling into that category.
It is great dogfood, but does lead to some head exploding debugging - you are looking at a piece of badly generated code trying to figure out how many generations back the bug is.