Revert the rest of the unnecessary changes

[bjorn3]

Before: Showing 69 changed files with 1,395 additions and 966 deletions. After: Showing 59 changed files with 1,334 additions and 952 deletions.

[vext01]

Yep. As you can see it's been quite an evolutionary journey so far!

bors r+

[bors[bot]]

Build succeeded:

• buildbot/ykrustc-buildbot-build-script-hwt