Investigation of xcortex

xcortex is a 256bits-hash solution using cvm ops.
It is following the design of randomx(monero), progpow and others.

It can include ops from cvm as needed to adjust the pow difficulty

Target is improve the cvm performance by pow mining way.

https://github.com/CortexFoundation/cvm-runtime
https://github.com/CortexFoundation/XCortex