If the blockchain in question is Turing-complete, then it would be possible (by trivial consequence of definition) to build an emulator for any other Turing-complete (or even non-Turing-complete) deterministic processor on the blockchain. However, the latency per operation would be prohibitively high for most purposes, unless each "CPU Instruction" is complex enough to greatly stretch definitions and lose meaningful distinctions.
So, the answer to the most strait forward interpretation of your question is basically "Yes, it's obviously possible and likely trivial, but probably not practical"
So, the answer to the most strait forward interpretation of your question is basically "Yes, it's obviously possible and likely trivial, but probably not practical"