update EXTCODE* behavior in 7702 (#1094)

See https://github.com/ethereum/EIPs/pull/9248/files

Author: gurukamath

src/ethereum/prague/vm/eoa_delegation.py

@@ -21,7 +21,6 @@
 
 SET_CODE_TX_MAGIC = b"\x05"
 EOA_DELEGATION_MARKER = b"\xEF\x01\x00"
-EOA_DELEGATION_SENTINEL = b"\xEF\x01"
 EOA_DELEGATION_MARKER_LENGTH = len(EOA_DELEGATION_MARKER)
 EOA_DELEGATED_CODE_LENGTH = 23
 PER_EMPTY_ACCOUNT_COST = 25000

src/ethereum/prague/vm/instructions/environment.py

@@ -21,7 +21,6 @@
 from ...fork_types import EMPTY_ACCOUNT
 from ...state import get_account
 from ...utils.address import to_address
-from ...vm.eoa_delegation import EOA_DELEGATION_SENTINEL, is_valid_delegation
 from ...vm.memory import buffer_read, memory_write
 from .. import Evm
 from ..exceptions import OutOfBoundsRead
@@ -353,8 +352,6 @@ def extcodesize(evm: Evm) -> None:
 
     # OPERATION
     code = get_account(evm.env.state, address).code
-    if is_valid_delegation(code):
-        code = EOA_DELEGATION_SENTINEL
 
     codesize = U256(len(code))
     push(evm.stack, codesize)
@@ -397,8 +394,6 @@ def extcodecopy(evm: Evm) -> None:
     # OPERATION
     evm.memory += b"\x00" * extend_memory.expand_by
     code = get_account(evm.env.state, address).code
-    if is_valid_delegation(code):
-        code = EOA_DELEGATION_SENTINEL
 
     value = buffer_read(code, code_start_index, size)
     memory_write(evm.memory, memory_start_index, value)
@@ -490,8 +485,6 @@ def extcodehash(evm: Evm) -> None:
         codehash = U256(0)
     else:
         code = account.code
-        if is_valid_delegation(code):
-            code = EOA_DELEGATION_SENTINEL
         codehash = U256.from_be_bytes(keccak256(code))
 
     push(evm.stack, codehash)