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

[Julian Schmidt via cfe-commits]

https://github.com/5chmidti commented:

> 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.

IMO it is better as a follow-up so that the diff of the commit stays readable, which can also remove duplicate tests.

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