Add support for using GHC's -jsem option (backport #9139)

[mergify]

This is an automatic backport of pull request #9139 done by Mergify.
Cherry-pick of 0a1c167 has failed:

On branch mergify/bp/3.10/pr-9139
Your branch is up to date with 'origin/3.10'.

You are currently cherry-picking commit 0a1c167a7.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   Cabal/Cabal.cabal
	new file:   Cabal/src/Distribution/Types/ParStrat.hs
	modified:   bootstrap/linux-8.10.7.json
	modified:   bootstrap/linux-9.0.2.json
	modified:   bootstrap/linux-9.2.8.json
	modified:   cabal-install/cabal-install.cabal
	modified:   cabal-install/tests/IntegrationTests2.hs
	new file:   cabal-testsuite/PackageTests/NewBuild/Semaphore/C.hs
	new file:   cabal-testsuite/PackageTests/NewBuild/Semaphore/Semaphore.cabal
	new file:   cabal-testsuite/PackageTests/NewBuild/Semaphore/Setup.hs
	new file:   cabal-testsuite/PackageTests/NewBuild/Semaphore/cabal.out
	new file:   cabal-testsuite/PackageTests/NewBuild/Semaphore/cabal.project
	new file:   cabal-testsuite/PackageTests/NewBuild/Semaphore/cabal.test.hs
	new file:   cabal-testsuite/PackageTests/NewBuild/Semaphore/sub-package-A/A.hs
	new file:   cabal-testsuite/PackageTests/NewBuild/Semaphore/sub-package-A/Setup.hs
	new file:   cabal-testsuite/PackageTests/NewBuild/Semaphore/sub-package-A/sub-package-A.cabal
	new file:   cabal-testsuite/PackageTests/NewBuild/Semaphore/sub-package-B/B.hs
	new file:   cabal-testsuite/PackageTests/NewBuild/Semaphore/sub-package-B/Setup.hs
	new file:   cabal-testsuite/PackageTests/NewBuild/Semaphore/sub-package-B/sub-package-B.cabal
	new file:   changelog.d/pr-8557
	new file:   changelog.d/pr-8557-2
	modified:   doc/cabal-project.rst

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	both modified:   Cabal/src/Distribution/Simple/Build.hs
	both modified:   Cabal/src/Distribution/Simple/Compiler.hs
	both modified:   Cabal/src/Distribution/Simple/GHC.hs
	both modified:   Cabal/src/Distribution/Simple/GHCJS.hs
	both modified:   Cabal/src/Distribution/Simple/Program/GHC.hs
	both modified:   Cabal/src/Distribution/Simple/Setup.hs
	deleted by us:   Cabal/src/Distribution/Simple/Setup/Build.hs
	both modified:   bootstrap/linux-9.4.5.json
	both modified:   cabal-install/src/Distribution/Client/Config.hs
	both modified:   cabal-install/src/Distribution/Client/JobControl.hs
	both modified:   cabal-install/src/Distribution/Client/ProjectBuilding.hs
	both modified:   cabal-install/src/Distribution/Client/ProjectConfig.hs
	both modified:   cabal-install/src/Distribution/Client/ProjectConfig/Legacy.hs
	both modified:   cabal-install/src/Distribution/Client/ProjectConfig/Types.hs
	both modified:   cabal-install/src/Distribution/Client/ProjectPlanning.hs
	both modified:   cabal-install/src/Distribution/Client/Setup.hs
	both modified:   cabal-install/tests/UnitTests/Distribution/Client/ProjectConfig.hs

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/github/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

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[Kleidukos]

hmm fuck.

[ulysses4ever]

Hey! Just wanted to double-check: are we changing the policy for point releases to be bug fix only?

[Kleidukos]

I wanted to see if that one was free. :p But hopefully by the time 9.8 arrives and is widely used, we'll have 3.12 as the new cabal stable

[ulysses4ever]

By all means! I'm also eager to have this in a release but it's a sizeable patch, and I just wanted to play cautious here...

[Mikolaj]

Now that the experiment is through, could you close the PR?