core/state: fix incorrect description of function behavior (ethereum#31809)

Author: klim0v

core/state/statedb.go

@@ -298,7 +298,7 @@ func (s *StateDB) SubRefund(gas uint64) {
 }
 
 // Exist reports whether the given account address exists in the state.
-// Notably this also returns true for self-destructed accounts.
+// Notably this also returns true for self-destructed accounts within the current transaction.
 func (s *StateDB) Exist(addr common.Address) bool {
 	return s.getStateObject(addr) != nil
 }

core/vm/interface.go

@@ -69,7 +69,7 @@ type StateDB interface {
 	SelfDestruct6780(common.Address) (uint256.Int, bool)
 
 	// Exist reports whether the given account exists in state.
-	// Notably this should also return true for self-destructed accounts.
+	// Notably this also returns true for self-destructed accounts within the current transaction.
 	Exist(common.Address) bool
 	// Empty returns whether the given account is empty. Empty
 	// is defined according to EIP161 (balance = nonce = code = 0).