The tests need to run with certain environment variables set that only
cmake really knows and that differ between stages. Cmake could just set
the variables directly when running the tests and benchmarks, but that
would leave no good way to manually run a single benchmark. So cmake
generates some stage-specific scripts instead that set the required
environment variables.
Previously, those scripts were sourced directly by the individual
`run_*` scripts, so the env scripts of different stages would overwrite
each other. This PR changes the setup so they can instead be generated
next to each other. This also simplifies the `run_*` scripts themselves
a bit, and makes `tests/bench/build` less of a hack.
This PR changes all `lean-toolchain` to use relative toolchain paths
instead of `lean4` and `lean4-stage0` identifiers, which removes the
need for manually linking toolchains via Elan.
After this PR, at least Elan 4.2.0 and 0.0.224 of the Lean VS Code
extension will be needed to edit core.
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
