add #[inline(always)] to From<HashMap> impl

Author: overlookmotel

crates/oxc_allocator/src/hash_set.rs

@@ -198,7 +198,11 @@ impl<T> Eq for HashSet<'_, T> where T: Eq + Hash {}
 
 // Note: `Index` and `Extend` are implemented via `Deref`
 
+/// Convert `HashMap<T, ()>` to `HashSet<T>`.
+///
+/// This conversion is zero cost, as `HashSet<T>` is just a wrapper around `HashMap<T, ()>`.
 impl<'alloc, T> From<HashMap<'alloc, T, ()>> for HashSet<'alloc, T> {
+    #[inline(always)]
     fn from(map: HashMap<'alloc, T, ()>) -> Self {
         let inner_map = ManuallyDrop::into_inner(map.0);
         let inner_set = hashbrown::HashSet::from(inner_map);