Fix a few typos in SPIRV translation comments.
Fix a few typos in SPIRV translation comments.

Closes #4

COPYBARA_INTEGRATE_REVIEW=https://github.com/google/iree/pull/4 from google:typo-fix 59f67c689605ea776c53a4cf77889462a5c963a1
PiperOrigin-RevId: 271213192

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