Turbopack: fix and finish immutable tasks (#80996)

### What?

Fixes the problems with the implementation of immutable tasks, adds tests and debug asserts to ensure it's working.

* There was some confusion between children and dependencies. Children are not involved with immutablility, only dependencies are.
* Opt out of immutablility for reading collectibles and for getting an invalidator.
* Removed `#[turbo_tasks::function(invalidator)]` and the logic of discovering statically immutable with macro code. It won't work as local tasks are invisible and can cause dependencies


Follow-up changes:
* Technically immutability could be per cell instead of per task. A task produces immutable cells until it does something that depends on mutable cells or other opt-outs. It could be `RawVc::ImmutableCell` and the immutable flag would be only in `InProgressState` and not on a task.

Author: sokra

crates/next-api/src/project.rs

@@ -431,7 +431,7 @@ impl ProjectContainer {
 
 #[turbo_tasks::value_impl]
 impl ProjectContainer {
-    #[turbo_tasks::function(invalidator)]
+    #[turbo_tasks::function]
     pub async fn project(&self) -> Result<Vc<Project>> {
         let env_map: Vc<EnvMap>;
         let next_config;

crates/next-api/src/versioned_content_map.rs

@@ -213,7 +213,7 @@ impl VersionedContentMap {
         Ok(Vc::cell(None))
     }
 
-    #[turbo_tasks::function(invalidator)]
+    #[turbo_tasks::function]
     pub async fn keys_in_path(&self, root: FileSystemPath) -> Result<Vc<Vec<RcStr>>> {
         let keys = {
             let map = &self.map_path_to_op.get().0;
@@ -230,7 +230,7 @@ impl VersionedContentMap {
         Ok(Vc::cell(keys))
     }
 
-    #[turbo_tasks::function(invalidator)]
+    #[turbo_tasks::function]
     fn raw_get(&self, path: FileSystemPath) -> Vc<OptionMapEntry> {
         let assets = {
             let map = &self.map_path_to_op.get().0;

packages/next/src/build/swc/generated-native.d.ts

@@ -107,7 +107,7 @@ export interface NapiProjectOptions {
   /** A path inside the root_path which contains the app/pages directories. */
   projectPath: RcStr
   /**
-   * next.config's distDir. Project initialization occurs eariler than
+   * next.config's distDir. Project initialization occurs earlier than
    * deserializing next.config, so passing it as separate option.
    */
   distDir: RcStr
@@ -153,7 +153,7 @@ export interface NapiPartialProjectOptions {
   /** A path inside the root_path which contains the app/pages directories. */
   projectPath?: RcStr
   /**
-   * next.config's distDir. Project initialization occurs eariler than
+   * next.config's distDir. Project initialization occurs earlier than
    * deserializing next.config, so passing it as separate option.
    */
   distDir?: RcStr | undefined | null

turbopack/crates/turbo-tasks-backend/Cargo.toml

@@ -17,6 +17,7 @@ default = []
 print_cache_item_size = []
 verify_serialization = []
 verify_aggregation_graph = []
+verify_immutable = []
 trace_aggregation_update = []
 trace_find_and_schedule = []
 trace_task_completion = []