fix: auto-create the burnt funds account (#1894)

The FVM relies on this so it can burn funds on self-destruct.

testing/integration/src/builtin.rs

@@ -2,11 +2,12 @@
 // SPDX-License-Identifier: Apache-2.0, MIT
 use anyhow::{Context, Result};
 use cid::Cid;
-use fvm::machine::Manifest;
+use fvm::machine::{Manifest, BURNT_FUNDS_ACTOR_ID};
 use fvm::state_tree::{ActorState, StateTree};
 use fvm::{init_actor, system_actor};
 use fvm_ipld_blockstore::Blockstore;
 use fvm_ipld_encoding::CborStore;
+use fvm_shared::address::Address;
 use fvm_shared::ActorID;
 use multihash::Code;
 
@@ -90,3 +91,28 @@ pub fn set_eam_actor(state_tree: &mut StateTree<impl Blockstore>, eam_code_cid:
     state_tree.set_actor(EAM_ACTOR_ID, eam_actor_state);
     Ok(())
 }
+
+pub fn set_burnt_funds_account(
+    state_tree: &mut StateTree<impl Blockstore>,
+    account_code_cid: Cid,
+) -> Result<()> {
+    let state = fvm::account_actor::State {
+        address: Address::new_id(BURNT_FUNDS_ACTOR_ID),
+    };
+
+    let account_state_cid = state_tree
+        .store()
+        .put_cbor(&state, Code::Blake2b256)
+        .context(FailedToSetState("burnt funds account actor".to_owned()))?;
+
+    let actor_state = ActorState {
+        code: account_code_cid,
+        state: account_state_cid,
+        sequence: 0,
+        balance: Default::default(),
+        delegated_address: None,
+    };
+
+    state_tree.set_actor(BURNT_FUNDS_ACTOR_ID, actor_state);
+    Ok(())
+}

testing/integration/src/tester.rs

@@ -20,7 +20,9 @@ use lazy_static::lazy_static;
 use libsecp256k1::{PublicKey, SecretKey};
 use multihash::Code;
 
-use crate::builtin::{fetch_builtin_code_cid, set_eam_actor, set_init_actor, set_sys_actor};
+use crate::builtin::{
+    fetch_builtin_code_cid, set_burnt_funds_account, set_eam_actor, set_init_actor, set_sys_actor,
+};
 use crate::dummy::DummyExterns;
 use crate::error::Error::{FailedToFlushTree, NoManifestInformation};
 
@@ -96,10 +98,11 @@ where
         let init_state = init_actor::State::new_test(&blockstore);
         let mut state_tree = StateTree::new(blockstore, stv).map_err(anyhow::Error::from)?;
 
-        // Deploy init, sys, and eam actors
+        // Deploy init, sys, burn, and eam actors
         let sys_state = system_actor::State { builtin_actors };
         set_sys_actor(&mut state_tree, sys_state, sys_code_cid)?;
         set_init_actor(&mut state_tree, init_code_cid, init_state)?;
+        set_burnt_funds_account(&mut state_tree, accounts_code_cid)?;
         set_eam_actor(&mut state_tree, eam_code_cid)?;
 
         Ok(Tester {