[clang] [clang-tools-extra] [analyzer] Remove alpha.core.IdenticalExpr Checker (PR #114715)

[via cfe-commits]

vabridgers wrote:

I've reworked the test port in a "scaffolded" way so reviewers may see how the cases were considered one by one, and the existing tidy checkers improved to address cases IdenticalExpr was detecting and the tidy checkers were not. I needed to weaken the misc-redundant-expression AST matcher a bit, and consider an extra case for the bugprone-branch-clone checker. This picked up the integer and floating point literal cases, and also the duplicate outer/inner if cases. 

I'm happy to take next suggested steps to drive this improvement to completion, and would like some guidance on if the additional "scaffolded" case should be kept in place (to maintain clear differences from the original to new file in the git diff), or split the file now or maybe in a future separate commit so the differences are clear. 

Thanks - Vince 

https://github.com/llvm/llvm-project/pull/114715