stablize const_binary_heap_constructor & create an unstable feature const_binary_heap_new_in for BinaryHeap::new_in

Author: Coekjan

alloc/src/collections/binary_heap/mod.rs

@@ -440,7 +440,10 @@ impl<T: Ord> BinaryHeap<T> {
     /// heap.push(4);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "const_binary_heap_constructor", issue = "112353")]
+    #[rustc_const_stable(
+        feature = "const_binary_heap_constructor",
+        since = "CURRENT_RUSTC_VERSION"
+    )]
     #[must_use]
     pub const fn new() -> BinaryHeap<T> {
         BinaryHeap { data: vec![] }
@@ -484,7 +487,7 @@ impl<T: Ord, A: Allocator> BinaryHeap<T, A> {
     /// heap.push(4);
     /// ```
     #[unstable(feature = "allocator_api", issue = "32838")]
-    #[rustc_const_unstable(feature = "const_binary_heap_constructor", issue = "112353")]
+    #[rustc_const_unstable(feature = "const_binary_heap_new_in", issue = "112353")]
     #[must_use]
     pub const fn new_in(alloc: A) -> BinaryHeap<T, A> {
         BinaryHeap { data: Vec::new_in(alloc) }