[clang] Allow the no_stack_protector attribute on local variables (PR #173311)

[Aaron Ballman via cfe-commits]

https://github.com/AaronBallman commented:

The changes should also come with a release note in `clang/docs/ReleaseNotes.rst` and `clang/include/clang/Basic/AttrDocs.td` needs to have `NoStackProtectorDocs` updated as well.

https://github.com/llvm/llvm-project/pull/173311