stop special-casing futex creation on macOS

Author: joboet

src/shims/unix/macos/sync.rs

@@ -143,16 +143,15 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             .read_scalar_atomic(&this.ptr_to_mplace(ptr, layout), AtomicReadOrd::Acquire)?
             .to_bits(Size::from_bytes(size))?;
 
-        let Some(futex) = this.get_sync_or_init(ptr, |_| {
-            MacOsFutex {
-                futex: Default::default(),
-                size: Cell::new(size),
-                shared: Cell::new(is_shared),
-            }
-        }) else {
-            this.set_last_error_and_return(LibcError("ENOMEM"), dest)?;
-            return interp_ok(());
-        };
+        let futex = this
+            .get_sync_or_init(ptr, |_| {
+                MacOsFutex {
+                    futex: Default::default(),
+                    size: Cell::new(size),
+                    shared: Cell::new(is_shared),
+                }
+            })
+            .unwrap();
 
         // Detect mismatches between the flags and sizes used on this address
         // by comparing with the parameters stored with the first waiter.