EVM: Implement & document the MCOPY opcode

[Stebalien]

We need to implement the proposed MCOPY opcode for the EVM actor.

In terms of implementation, we need to:

1. Map the opcode to the operation:

   builtin-actors/actors/evm/src/interpreter/execution.rs

   Lines 92 to 247 in 1e50065

   	pub mod opcodes {
   	use super::instructions;
   	use super::Machine;
   	use fil_actors_runtime::runtime::Runtime;
   	use fil_actors_runtime::ActorError;
   	pub(crate) type Instruction<'r, 'a, RT> =
   	unsafe fn(*mut Machine<'r, 'a, RT>) -> Result<(), ActorError>;
   	def_opcodes! {
   	0x00: STOP,
   	0x01: ADD,
   	0x02: MUL,
   	0x03: SUB,
   	0x04: DIV,
   	0x05: SDIV,
   	0x06: MOD,
   	0x07: SMOD,
   	0x08: ADDMOD,
   	0x09: MULMOD,
   	0x0a: EXP,
   	0x0b: SIGNEXTEND,
   	0x10: LT,
   	0x11: GT,
   	0x12: SLT,
   	0x13: SGT,
   	0x14: EQ,
   	0x15: ISZERO,
   	0x16: AND,
   	0x17: OR,
   	0x18: XOR,
   	0x19: NOT,
   	0x1a: BYTE,
   	0x1b: SHL,
   	0x1c: SHR,
   	0x1d: SAR,
   	0x20: KECCAK256,
   	0x30: ADDRESS,
   	0x31: BALANCE,
   	0x32: ORIGIN,
   	0x33: CALLER,
   	0x34: CALLVALUE,
   	0x35: CALLDATALOAD,
   	0x36: CALLDATASIZE,
   	0x37: CALLDATACOPY,
   	0x38: CODESIZE,
   	0x39: CODECOPY,
   	0x3a: GASPRICE,
   	0x3b: EXTCODESIZE,
   	0x3c: EXTCODECOPY,
   	0x3d: RETURNDATASIZE,
   	0x3e: RETURNDATACOPY,
   	0x3f: EXTCODEHASH,
   	0x40: BLOCKHASH,
   	0x41: COINBASE,
   	0x42: TIMESTAMP,
   	0x43: NUMBER,
   	0x44: PREVRANDAO,
   	0x45: GASLIMIT,
   	0x46: CHAINID,
   	0x47: SELFBALANCE,
   	0x48: BASEFEE,
   	0x50: POP,
   	0x51: MLOAD,
   	0x52: MSTORE,
   	0x53: MSTORE8,
   	0x54: SLOAD,
   	0x55: SSTORE,
   	0x56: JUMP,
   	0x57: JUMPI,
   	0x58: PC,
   	0x59: MSIZE,
   	0x5a: GAS,
   	0x5b: JUMPDEST,
   	0x5F: PUSH0,
   	0x60: PUSH1,
   	0x61: PUSH2,
   	0x62: PUSH3,
   	0x63: PUSH4,
   	0x64: PUSH5,
   	0x65: PUSH6,
   	0x66: PUSH7,
   	0x67: PUSH8,
   	0x68: PUSH9,
   	0x69: PUSH10,
   	0x6a: PUSH11,
   	0x6b: PUSH12,
   	0x6c: PUSH13,
   	0x6d: PUSH14,
   	0x6e: PUSH15,
   	0x6f: PUSH16,
   	0x70: PUSH17,
   	0x71: PUSH18,
   	0x72: PUSH19,
   	0x73: PUSH20,
   	0x74: PUSH21,
   	0x75: PUSH22,
   	0x76: PUSH23,
   	0x77: PUSH24,
   	0x78: PUSH25,
   	0x79: PUSH26,
   	0x7a: PUSH27,
   	0x7b: PUSH28,
   	0x7c: PUSH29,
   	0x7d: PUSH30,
   	0x7e: PUSH31,
   	0x7f: PUSH32,
   	0x80: DUP1,
   	0x81: DUP2,
   	0x82: DUP3,
   	0x83: DUP4,
   	0x84: DUP5,
   	0x85: DUP6,
   	0x86: DUP7,
   	0x87: DUP8,
   	0x88: DUP9,
   	0x89: DUP10,
   	0x8a: DUP11,
   	0x8b: DUP12,
   	0x8c: DUP13,
   	0x8d: DUP14,
   	0x8e: DUP15,
   	0x8f: DUP16,
   	0x90: SWAP1,
   	0x91: SWAP2,
   	0x92: SWAP3,
   	0x93: SWAP4,
   	0x94: SWAP5,
   	0x95: SWAP6,
   	0x96: SWAP7,
   	0x97: SWAP8,
   	0x98: SWAP9,
   	0x99: SWAP10,
   	0x9a: SWAP11,
   	0x9b: SWAP12,
   	0x9c: SWAP13,
   	0x9d: SWAP14,
   	0x9e: SWAP15,
   	0x9f: SWAP16,
   	0xa0: LOG0,
   	0xa1: LOG1,
   	0xa2: LOG2,
   	0xa3: LOG3,
   	0xa4: LOG4,
   	// 0xEF Reserved for EIP-3541
   	0xf0: CREATE,
   	0xf1: CALL,
   	0xf3: RETURN,
   	0xf4: DELEGATECALL,
   	0xf5: CREATE2,
   	0xfa: STATICCALL,
   	0xfd: REVERT,
   	0xfe: INVALID,
   	0xff: SELFDESTRUCT,
   	}
   	}

2. Implement the new instruction here. This instruction will look a lot like calldatacopy but we'll have to be careful because we'll be copying between two potentially overlapping slices in the same memory.
3. Bind the instruction to the instruction implementation (from step 2) with def_stdproc here.
4. Write a few unit tests:
   • Non-overlapping copy.
   • Overlapping copy.
   • Out of range dest.
   • Partially out of rage source (expands memory).
   • Fully out of range dest (fails).

Finally, we'll need to write a FIP, which shouldn't be particularly controversial. You can also start with the FIP but it often helps to take a stab at the implementation first.

[maciejwitowski]

From huddle: we expect this to be adopted immediately after upgrade since the Solidity compiler will output it.

[aarshkshah1992]

I would LOVE to work on this and ship it e2e from FIP -> mainnet.

[aarshkshah1992]

@raulk @Stebalien Please can one of you elaborate on the impact to users of shipping this ? Is the main win here that builders on FEVM no longer need to rely on outdated versions of Solidity compiler ?