Add extension that enables CONFIG_RUST in kernel menuconfig and
configures the build environment (rustc, rustfmt, bindgen, rust-src)
using versioned APT packages from noble-security/noble-updates.
Handles env -i in run_kernel_make_internal by passing tool paths
via RUSTC, RUSTFMT, BINDGEN make params and RUST_LIB_SRC env var.
Includes optional RUST_KERNEL_SAMPLES=yes for building sample
Rust modules (rust_minimal, rust_print, rust_driver_faux) as a
toolchain smoke test.
Tested: kernel 6.19 build for rockchip64 on aarch64, both with
and without Docker.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
