[clang] [analyzer] Move alpha checker EnumCastOutOfRange to optin (PR #67157)

[Gábor Horváth via cfe-commits]

Xazax-hun wrote:

I am a bit concerned about the bad user experience with bitwise enums, but I think that is probably OK since this is an optin check. That being said, I think:
* It would be easy to address this, there is already a clang tidy check for bitwise enums, the heuristics to recognize them could be reused from there and used to suppress bogus warnings.
* As long as this limitation is documented, I am happy to get this merged as is.

https://github.com/llvm/llvm-project/pull/67157