[llvm][NFC] Inclusive language: Reword replace uses of sanity in...

[llvm][NFC] Inclusive language: Reword replace uses of sanity in llvm/lib/Transform comments and asserts

Reworded some comments and asserts to avoid usage of `sanity check/test`

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D114372