Sync `par_sort*` with the standard library #459

	name: PR
	on: pull_request

	# Using 16MB stacks for deep test/debug recursion
	env:
	RUST_MIN_STACK: 16777216

	jobs:

	check:
	name: Check (1.63.0)
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4
	- uses: actions/cache@v4
	with:
	path: ~/.cargo/registry/index
	key: cargo-git-index
	- uses: dtolnay/rust-toolchain@1.63.0
	- run: cp ci/compat-Cargo.lock ./Cargo.lock
	- run: cargo check --verbose --locked

	test:
	name: Test (stable)
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4
	- uses: dtolnay/rust-toolchain@stable
	- run: cargo build --verbose
	- run: cargo test --verbose --package rayon
	- run: cargo test --verbose --package rayon-core
	- run: ./ci/highlander.sh

	fmt:
	name: Format
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4
	- uses: dtolnay/rust-toolchain@1.72.1
	with:
	components: rustfmt
	- run: cargo fmt --all --check

	# One job that "summarizes" the success state of this pipeline. This can then be added to branch
	# protection, rather than having to add each job separately.
	success:
	name: Success
	runs-on: ubuntu-latest
	needs: [check, test, fmt]
	# Github branch protection is exceedingly silly and treats "jobs skipped because a dependency
	# failed" as success. So we have to do some contortions to ensure the job fails if any of its
	# dependencies fails.
	if: always() # make sure this is never "skipped"
	steps:
	# Manually check the status of all dependencies. `if: failure()` does not work.
	- name: check if any dependency failed
	run: jq --exit-status 'all(.result == "success")' <<< '${{ toJson(needs) }}'

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