[clang] Make -frewrite-includes put an endif at the end of the included text (PR #67613)

[Erich Keane via cfe-commits]

https://github.com/erichkeane commented:

The clang-format tool still has a complaint, so this isn't passing CI.  Unfortunately it doesn't seem to print it in the CI, so you'll have to run it locally.  Delta that, LGTM.

https://github.com/llvm/llvm-project/pull/67613