chore(turbo-tasks): Add test for argument filtering (#75585)

This is a follow-up to: #75261

Tracking issue for these follow-ups: https://linear.app/vercel/issue/PACK-3828/argument-filtering-follow-ups

turbopack/crates/turbo-tasks-backend/tests/filter_unused_args.rs

@@ -0,0 +1 @@
+../../turbo-tasks-testing/tests/filter_unused_args.rs

turbopack/crates/turbo-tasks-memory/tests/filter_unused_args.rs

@@ -0,0 +1 @@
+../../turbo-tasks-testing/tests/filter_unused_args.rs

turbopack/crates/turbo-tasks-testing/tests/filter_unused_args.rs

@@ -0,0 +1,64 @@
+#![feature(arbitrary_self_types)]
+#![feature(arbitrary_self_types_pointers)]
+#![allow(clippy::needless_return)] // tokio macro-generated code doesn't respect this
+
+use anyhow::Result;
+use turbo_tasks::Vc;
+use turbo_tasks_testing::{register, run, Registration};
+
+static REGISTRATION: Registration = register!();
+
+#[tokio::test]
+async fn filtered_trait_method_args() -> Result<()> {
+    run(&REGISTRATION, || async {
+        let uses_arg = UsesArg.cell();
+        assert_eq!(
+            uses_arg.method_with_arg(0).to_resolved().await?,
+            uses_arg.method_with_arg(0).to_resolved().await?,
+        );
+        assert_ne!(
+            uses_arg.method_with_arg(0).to_resolved().await?,
+            uses_arg.method_with_arg(1).to_resolved().await?,
+        );
+
+        let ignores_arg = IgnoresArg.cell();
+        assert_eq!(
+            ignores_arg.method_with_arg(0).to_resolved().await?,
+            ignores_arg.method_with_arg(0).to_resolved().await?,
+        );
+        assert_eq!(
+            ignores_arg.method_with_arg(0).to_resolved().await?,
+            ignores_arg.method_with_arg(1).to_resolved().await?,
+        );
+        Ok(())
+    })
+    .await
+}
+
+#[turbo_tasks::value_trait]
+trait ExampleTrait {
+    fn method_with_arg(&self, number: i32) -> Vc<()>;
+}
+
+#[turbo_tasks::value]
+struct UsesArg;
+
+#[turbo_tasks::value_impl]
+impl ExampleTrait for UsesArg {
+    #[turbo_tasks::function]
+    fn method_with_arg(&self, number: i32) -> Vc<()> {
+        let _ = number;
+        Vc::cell(())
+    }
+}
+
+#[turbo_tasks::value]
+struct IgnoresArg;
+
+#[turbo_tasks::value_impl]
+impl ExampleTrait for IgnoresArg {
+    #[turbo_tasks::function]
+    fn method_with_arg(&self, _number: i32) -> Vc<()> {
+        Vc::cell(())
+    }
+}