chore: checkpoint before Python removal

vendor/smallvec/src/arbitrary.rs

@@ -0,0 +1,19 @@
+use crate::{Array, SmallVec};
+use arbitrary::{Arbitrary, Unstructured};
+
+impl<'a, A: Array> Arbitrary<'a> for SmallVec<A>
+where
+    <A as Array>::Item: Arbitrary<'a>,
+{
+    fn arbitrary(u: &mut Unstructured<'a>) -> arbitrary::Result<Self> {
+        u.arbitrary_iter()?.collect()
+    }
+
+    fn arbitrary_take_rest(u: Unstructured<'a>) -> arbitrary::Result<Self> {
+        u.arbitrary_take_rest_iter()?.collect()
+    }
+
+    fn size_hint(depth: usize) -> (usize, Option<usize>) {
+        arbitrary::size_hint::and(<usize as Arbitrary>::size_hint(depth), (0, None))
+    }
+}