[clang] [Clang][Sema] Warn when 'exclude_from_explicit_instantiation' attribute is used on local classes and members thereof (PR #88777)

[Krystian Stasiowski via cfe-commits]

sdkrystian wrote:

@erichkeane Perhaps the release note should go under "Attribute Changes in Clang"?

https://github.com/llvm/llvm-project/pull/88777