NVIDIA releases cuda-oxide, a Rust-to-PTX compiler backend

NVlabs published cuda-oxide v0.1.0, a custom rustc codegen backend that compiles `#[kernel]`-annotated Rust functions to PTX via Stable MIR → Pliron IR → LLVM IR. Single-source host+device builds run from one `cargo oxide build` command. It's NVIDIA's most serious move yet to bring Rust into the CUDA toolchain.