Recover feature lang_items for emscripten

[mu001999]

Fixes #152469 (comment)

[rustbot]

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[joboet]

@bors r+ rollup

[rust-bors]

📌 Commit d79efc5 has been approved by joboet

It is now in the queue for this repository.

[kleisauke]

This should probably be:

Suggested change

	#![cfg_attr(all(target_os = "emscripten", not(emscripten_wasm_eh)), lang_items)]
	#![cfg_attr(all(target_os = "emscripten", not(emscripten_wasm_eh)), feature(lang_items))]

(untested)

See:

error: cannot find attribute `lang_items` in this scope
  --> /rustc/38c0de8dcb14d42290042521be9958d37f3fa390/library/panic_unwind/src/lib.rs:17:69
   |
17 | #![cfg_attr(all(target_os = "emscripten", not(emscripten_wasm_eh)), lang_items)]
   |                                                                     ^^^^^^^^^^

error[E0658]: lang items are subject to change
  --> /rustc/38c0de8dcb14d42290042521be9958d37f3fa390/library/panic_unwind/src/emcc.rs:40:1
   |
40 | #[lang = "eh_catch_typeinfo"]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: add `#![feature(lang_items)]` to the crate attributes to enable
   = note: this compiler was built on 2026-02-28; consider upgrading it if it is out of date

For more information about this error, try `rustc --explain E0658`.
error: could not compile `panic_unwind` (lib) due to 2 previous errors

[mu001999]

Awkward😅

[joboet]

Whoops... 😄