Improve Offload artifact creation

[ZuseZ4]

I think the underlying problem is that we don't treat these artifacts (especially device.bin, less the Host Manifest) as proper rust options to --emit. We could change that, but I'm not sure if it's the right path forward, given that it's just a glorified bit code wrapper. I feel like we can probably drop it (along with using some LLVM APIs) by just passing the bitcode files around. I mainly need to figure out which other tooling we might have access too if we keep following their bundle workflow.

[rust-log-analyzer]

The job tidy failed! Check out the build log: (web) (plain enhanced) (plain)

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fmt: checked 7244 files
tidy check
tidy [rustdoc_json (src)]: `rustdoc-json-types` modified, checking format version
tidy: Skipping binary file check, read-only filesystem
tidy [style (compiler)]: /checkout/compiler/rustc_codegen_llvm/src/back/offload.rs:2: \
Use a single space after dots in comments.
tidy [style (compiler)]: FAIL
removing old virtual environment
creating virtual environment at '/checkout/obj/build/venv' using 'python3.12' and 'venv'
Requirement already satisfied: pip in ./build/venv/lib/python3.12/site-packages (24.0)
Collecting pip
  Downloading pip-26.2.1-py3-none-any.whl.metadata (4.6 kB)
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typechecking javascript files
tidy: The following check failed: style (compiler)
Bootstrap failed while executing `test src/tools/tidy tidyselftest --extra-checks=py,cpp,js,spellcheck`
Currently active steps:
test::Tidy {  } at src/bootstrap/src/core/build_steps/test.rs:1665
Command `/checkout/obj/build/x86_64-unknown-linux-gnu/stage1-tools-bin/rust-tidy --root-path=/checkout --cargo-path=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo --output-dir=/checkout/obj/build --concurrency=4 --npm-path=/node/bin/yarn --ci=true --extra-checks=py,cpp,js,spellcheck` failed with exit code 1
Created at: src/bootstrap/src/core/build_steps/tool.rs:1627:23
Executed at: src/bootstrap/src/core/build_steps/test.rs:1747:29

Command has failed. Rerun with -v to see more details.
Build completed unsuccessfully in 0:02:35
  local time: Fri Sep  4 16:41:30 UTC 2026
  network time: Fri, 04 Sep 2026 16:41:30 GMT
##[error]Process completed with exit code 1.
##[group]Run echo "disk usage:"