Most of the VM is written in C. Only the core of the interpreter is written in assembler (generates ~13K of machine code). And the port of the interpreter to x

Most of the VM is written in C. Only the core of the interpreter is written in assembler (generates ~13K of machine code). And the port of the interpreter to x64 is already done, so it was certainly practical. Porting the rest of the VM and the JIT compiler is what takes most of the time.