Revert "SI-8315 Better debugging facility for ICode"

This reverts commit 0561dd084b5f3c2678eb032a40b85cb25bb6d589.

When the windows nightly broke, git bisect pointed its unwavering finger at this poor soul.

Build passes again after the revert: https://scala-webapps.epfl.ch/jenkins/job/scala-checkin-manual-windows/39/console

I have no idea why, but the machines don't lie (and I don't have time right now to dig deeper).
Ok, if I had to guess, I'd say the longer filenames for the .icode files confused windows somehow.