Rollup merge of rust-lang#113568 - ferrocene:pa-spurious-weak-lang-item-2, r=b-naber

Fix spurious test failure with `panic=abort`

Description on why it happens and why the fix should work is in the code comments.

Author: matthiaskrgr

tests/ui/panic-handler/weak-lang-item-2.rs

@@ -1,15 +1,15 @@
 // run-pass
 // aux-build:weak-lang-items.rs
 
-// ignore-emscripten no threads support
 // pretty-expanded FIXME #23616
 
 extern crate weak_lang_items as other;
 
-use std::thread;
-
 fn main() {
-    let _ = thread::spawn(move|| {
-        other::foo()
-    });
+    // The goal of the test is just to make sure other::foo() is referenced at link time. Since
+    // the function panics, to prevent it from running we gate it behind an always-false `if` that
+    // is not going to be optimized away.
+    if std::hint::black_box(false) {
+        other::foo();
+    }
 }