This reverts commit a240ccd8, reversing
changes made to 393fdc10.

This PR was likely responsible for a relatively large regression in
dist-x86_64-msvc-alt builder times, from approximately 1.7 to 2.8 hours,
bringing that builder into the pool of the slowest builders we currently have.

This seems to be limited to the alt builder due to needing parallel-compiler
enabled, likely leading to slow LLVM compilation for some reason.