[clang] [Clang] Remove unused TokenKey::KEYNOZOS (PR #207132)

[Cyrus Ding via cfe-commits]

dingcyrus wrote:

> the CI failure is related. Did you run the tests locally?

Thanks for catching this! The CI failure was caused by keywords that combine KEYALL with other flags —volatile uses KEYALL/KEYNOHLSL and _Atomic uses KEYALL/KEYNOOPENCIL. These don't match the if (Flags == KEYALL) fact path, so they go through the per-bit loop in getKeywordStatus. Removing KEYNOZOS from the enum without excluding its bit from KEYALL left an orphaned bit (0x4000000) that would hit llvm_unreachable in getKeywordStatusHelper's default case.

I've updated the patch to explicitly exclude the reserved bit from KEYALL. My local testing used LLVM_ENABLE_ASSERTIONS=OFF, which is why I didn't catch it —llvm_unreachable only fires with assertions enabled.

https://github.com/llvm/llvm-project/pull/207132