Revert "[clang-format] Remove the dependency on frontend"

This reverts commit ec66603ac7ea655be5c2c5f508c5bf0d5eaeb65b. It was
causing ubsan failures like the following on the ubsan bot:
llvm/lib/Support/SourceMgr.cpp:440:48: runtime error: pointer index expression with base 0x000000000000 overflowed to 0xfffffffffffffffa

GitOrigin-RevId: efed314118c7c287a71b8a8d67953a98d8a718d5
2 files changed