1. **Reexports `LIBDEVICE_BITCODE` for cleaner dependency usage:** The `LIBDEVICE_BITCODE` symbol from the `cust_raw::nvvm_sys` crate is now reexported via the `nvvm` crate. This allows consuming crates to access the symbol directly from `nvvm`, abstracting away the internal structure and reducing tight coupling to `cust_raw`.
2. **Simplifies dependency graph and usage of NVVM internals:** By removing the direct dependency on `cust_raw` from `rustc_codegen_nvvm`, the changes streamline the crate's external interface, reducing maintenance overhead and improving modularity. Consumers now only need to rely on the higher-level `nvvm` crate.
3. **Improves code readability and encapsulation:** The change makes the source cleaner by reducing low-level, verbose paths like `nvvm_sys::LIBDEVICE_BITCODE` to a concise `LIBDEVICE_BITCODE`, enhancing readability and reinforcing a layered architecture.
4. **Maintains existing functionality:** The code logic remains unchanged in behavior—`LIBDEVICE_BITCODE` is still used in the same way, ensuring that the refactor is safe, non-breaking, and purely organizational.