Turbopack: fix __dirname (#76902)

`__dirname` was always `undefined` due to a typo.
This was a regression from #75358, the PR restores the behavior of 15.1.7

Closes #76497
Closes PACK-4060

Author: mischnic

turbopack/crates/turbopack-ecmascript/src/chunk/item.rs

@@ -90,7 +90,7 @@ impl EcmascriptChunkItemContent {
         let mut args = vec![
             "g: global",
             // HACK
-            "d: __dirname",
+            "__dirname",
         ];
         if self.options.async_module.is_some() {
             args.push("a: __turbopack_async_module__");

turbopack/crates/turbopack-ecmascript/src/runtime_functions.rs

@@ -79,6 +79,8 @@ pub const TURBOPACK_REQUIRE_STUB: &TurbopackRuntimeFunctionShortcut =
 pub const TURBOPACK_REQUIRE_REAL: &TurbopackRuntimeFunctionShortcut =
     &TurbopackRuntimeFunctionShortcut::new("__turbopack_context__.t", "t");
 
+/// Adding an entry to this list will automatically ensure that `__turbopack_XXX__` can be called
+/// from user code (by inserting a replacement into free_var_references)
 pub const TUBROPACK_RUNTIME_FUNCTION_SHORTCUTS: [(&str, &TurbopackRuntimeFunctionShortcut); 21] = [
     ("__turbopack_require__", TURBOPACK_REQUIRE),
     ("__turbopack_module_context__", TURBOPACK_MODULE_CONTEXT),

turbopack/crates/turbopack-tests/tests/execution/turbopack/code-gen/dirname-filename/input/index.js

@@ -0,0 +1,4 @@
+it('__dirname and __filename should be set', () => {
+  expect(__dirname).toMatch(/^\[project\]\/.*\/code-gen\/dirname-filename\/input\/index\.js \[test\] \(ecmascript\)$/)
+  expect(__filename).toMatch(/dirname-filename\/output\/.*.js$/);
+})

turbopack/crates/turbopack-tests/tests/snapshot/basic-tree-shake/dynamic-import/output/4c35f_tests_snapshot_basic-tree-shake_dynamic-import_input_index_92a5f455.js

@@ -2,7 +2,7 @@
 
 "[project]/turbopack/crates/turbopack-tests/tests/snapshot/basic-tree-shake/dynamic-import/input/lib.js [test] (ecmascript, async loader)": ((__turbopack_context__) => {
 
-var { g: global, d: __dirname } = __turbopack_context__;
+var { g: global, __dirname } = __turbopack_context__;
 {
 __turbopack_context__.v((parentImport) => {
     return Promise.all([