chore(tvix/tools): move weave to //users/edef

This is not a core Tvix tool, it's a tool that uses a Tvix component.

Change-Id: I705f2c4ab87f1512e005007c933e16b84ed4279f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12605
Reviewed-by: edef <edef@edef.eu>
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>

users/edef/weave/src/bytes.rs

@@ -0,0 +1,27 @@
+use owning_ref::{OwningRef, StableAddress};
+use polars::export::arrow::buffer::Buffer;
+use std::ops::Deref;
+
+/// An shared `[[u8; N]]` backed by a Polars [Buffer].
+pub type FixedBytes<const N: usize> = OwningRef<Bytes, [[u8; N]]>;
+
+/// Wrapper struct to make [Buffer] implement [StableAddress].
+/// TODO(edef): upstream the `impl`
+pub struct Bytes(pub Buffer<u8>);
+
+/// SAFETY: [Buffer] is always an Arc+Vec indirection.
+unsafe impl StableAddress for Bytes {}
+
+impl Bytes {
+    pub fn map<U: ?Sized>(self, f: impl FnOnce(&[u8]) -> &U) -> OwningRef<Self, U> {
+        OwningRef::new(self).map(f)
+    }
+}
+
+impl Deref for Bytes {
+    type Target = [u8];
+
+    fn deref(&self) -> &Self::Target {
+        &*self.0
+    }
+}