Add back emacs autosave to .gitignore
Add back emacs autosave to .gitignore

This got clobbered because I merged it wrong

Closes #173

COPYBARA_INTEGRATE_REVIEW=https://github.com/google/iree/pull/173 from google:gitignore c42b95f85511aaee567b0f1cfc92010b12e2c0e2
PiperOrigin-RevId: 283572047

google/iree,google/iree,google/iree,google/iree,iree-org/iree,iree-org/iree,google/iree,iree-org/iree,iree-org/iree,iree-org/iree,google/iree,iree-org/iree,google/iree,iree-org/iree