> How would you go about making that pile of garbage into something fast?
Make a Rosetta analog and translate to an instruction set that is amenable to efficient prediction, wide dispatch, etc., replacing all the iAPX hardware object oriented nonsense with conventional logic. If necessary, extend the CPU to accommodate whatever memory ordering behavior is necessary for efficient execution, ah la Apple Silicon ARM with x86 total store ordering.
Most CISC designs died. A large part of x86's survival is because it wasn't exceptionally CISC.