chore: checkpoint before Python removal

vendor/potential_utf/src/lib.rs

@@ -0,0 +1,33 @@
+// This file is part of ICU4X. For terms of use, please see the file
+// called LICENSE at the top level of the ICU4X source tree
+// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
+
+#![cfg_attr(not(any(test, doc)), no_std)]
+#![cfg_attr(
+    not(test),
+    deny(
+        clippy::indexing_slicing,
+        clippy::unwrap_used,
+        clippy::expect_used,
+        clippy::panic,
+        clippy::exhaustive_structs,
+        clippy::exhaustive_enums,
+        clippy::trivially_copy_pass_by_ref,
+        missing_debug_implementations,
+    )
+)]
+
+//! A crate providing unvalidated string and character types.
+
+#[cfg(feature = "alloc")]
+extern crate alloc;
+
+mod uchar;
+mod ustr;
+
+pub use uchar::PotentialCodePoint;
+pub use ustr::PotentialUtf16;
+pub use ustr::PotentialUtf8;
+
+#[cfg(feature = "writeable")]
+mod writeable;