chore: checkpoint before Python removal

vendor/hashbrown-0.15.5/src/util.rs

@@ -0,0 +1,38 @@
+// FIXME: Replace with `core::hint::{likely, unlikely}` once they are stable.
+#[cfg(feature = "nightly")]
+pub(crate) use core::intrinsics::{likely, unlikely};
+
+#[cfg(not(feature = "nightly"))]
+#[inline(always)]
+#[cold]
+fn cold_path() {}
+
+#[cfg(not(feature = "nightly"))]
+#[inline(always)]
+pub(crate) fn likely(b: bool) -> bool {
+    if b {
+        true
+    } else {
+        cold_path();
+        false
+    }
+}
+
+#[cfg(not(feature = "nightly"))]
+#[inline(always)]
+pub(crate) fn unlikely(b: bool) -> bool {
+    if b {
+        cold_path();
+        true
+    } else {
+        false
+    }
+}
+
+// FIXME: use strict provenance functions once they are stable.
+// Implement it with a transmute for now.
+#[inline(always)]
+#[allow(clippy::useless_transmute)] // clippy is wrong, cast and transmute are different here
+pub(crate) fn invalid_mut<T>(addr: usize) -> *mut T {
+    unsafe { core::mem::transmute(addr) }
+}