Currentl DomTreeNodeBase is using std::vectot to store it's children.
Using SmallVector should be more efficient in terms of compile-time.
A size of 4 seems to be the sweet-spot in terms of compile-time,
This results in the following geomean improvements
geomean insts max rss O3 -0.31 % +0.02 % ReleaseThinLTO -0.35 % -0.12 % ReleaseLTO -0.28 % -0.12 % O0 -0.06 % -0.02 % NewPM O3 -0.36 % +0.05 % ReleaseThinLTO (link only) -0.44 % -0.10 % ReleaseLTO-g (link only): -0.32 % -0.03 %
I am not sure if there's any other benefits of using std::vector over