[Idea] Fixed size encoding instead of LEB128

Considering that we currently encode integers as LEB128, could we add an option to not encode with LEB128 and emit fixed size integers? This would definitely help with performance.

Where are we emitting integers in that encoding?

If you mean in the crate metadata AFAIK we switched to LEB128 as it reduced the file size and I believe it was even a net improvement due to this.