Fix build of spin-timer example

Signed-off-by: Alex Crichton <alex@alexcrichton.com>

examples/spin-timer/src/lib.rs

@@ -1,10 +1,11 @@
 use std::collections::HashMap;
 
+use anyhow::Context;
 use clap::Args;
 use serde::{Deserialize, Serialize};
-use spin_app::MetadataKey;
-use spin_core::async_trait;
-use spin_trigger::{EitherInstance, TriggerAppEngine, TriggerExecutor};
+use spin_app::{AppComponent, MetadataKey};
+use spin_core::{async_trait, Engine, Instance, InstancePre, Store};
+use spin_trigger::{TriggerAppEngine, TriggerExecutor};
 
 wasmtime::component::bindgen!({
     path: ".",
@@ -62,6 +63,10 @@ impl TriggerExecutor for TimerTrigger {
 
     type RunConfig = CliArgs;
 
+    type InstancePre = InstancePre<RuntimeData>;
+
+    type Instance = Instance;
+
     async fn new(engine: spin_trigger::TriggerAppEngine<Self>) -> anyhow::Result<Self> {
         let speedup = engine
             .app()
@@ -113,15 +118,30 @@ impl TriggerExecutor for TimerTrigger {
         }
         Ok(())
     }
+
+    async fn instantiate_pre(
+        engine: &Engine<RuntimeData>,
+        component: &AppComponent,
+        _config: &TimerTriggerConfig,
+    ) -> anyhow::Result<InstancePre<RuntimeData>> {
+        let comp = component.load_component(engine).await?;
+        Ok(engine
+            .instantiate_pre(&comp)
+            .with_context(|| format!("Failed to instantiate component '{}'", component.id()))?)
+    }
+
+    async fn instantiate(
+        store: &mut Store<RuntimeData>,
+        pre: &Self::InstancePre,
+    ) -> anyhow::Result<Instance> {
+        pre.instantiate_async(store).await
+    }
 }
 
 impl TimerTrigger {
     async fn handle_timer_event(&self, component_id: &str) -> anyhow::Result<()> {
         // Load the guest...
         let (instance, mut store) = self.engine.prepare_instance(component_id).await?;
-        let EitherInstance::Component(instance) = instance else {
-            unreachable!()
-        };
         let instance = SpinTimer::new(&mut store, &instance)?;
         // ...and call the entry point
         instance.call_handle_timer_request(&mut store).await