[clang] [lldb] [llvm] [ADT] Mark StringSwitch Cases with 6+ arguments as deprecated. NFC. (PR #163405)

[Jakub Kuderski via cfe-commits]

kuhar wrote:

I'm going to pre-commit changes to the calls to .Cases before landing the deprecation to minimize potential churn if we need to revert the deprecation for code not built by CI that I might have missed.

https://github.com/llvm/llvm-project/pull/163405