EIP-4399: Supplant DIFFICULTY opcode with PREVRANDAO

[OlivierBBB]

EIP-4399: Supplant DIFFICULTY opcode with PREVRANDAO

Impact

The PREVRANDAO value will be in the block header. As such its value should be included into the BLOCKDATA module thus replacing the DIFFICULTY field.

Notes

The PREVRANDAO opcode will be made part of the BTC instruction family.
Renaming the DIFFICULTY and potentially adjusting its gas cost should suffice.

Besu requirement

Besu confirmed value will be available in block header.

For upgrades, refer to https://github.com/hyperledger/besu/blob/main/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/mainnet/MainnetProtocolSpecs.java

Test vectors

• stackOverflow
• OOGX with nonzero PREVRANDAO