Revert "Include package root dir in stage2 error messages"

This reverts commit 15a030ef3d2d68992835568f2fb9d5deab18f39f.

ast-check started crashing after this commit. Needs more QA before
merging.
6d47b4f39eAndrew Kelley committed on 6/28/2021, 12:30:29 AMparent15a030e
2 files changedLine totals unavailable