[clang-tools-extra] [wip][clang-tidy] Add new `bugprone-suspicious-pointer-arithmetics-using-sizeof` (`cert-arr39-c`) check (PR #106061)

[via cfe-commits]

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+//===--- SuspiciousPointerArithmeticsUsingSizeofCheck.h - clang-tidy -*- C++ -*-===//
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whisperity wrote:

This is not fixable without removing the `-*- C++ -*-` part, but that also should be there, because emacs users.

https://github.com/llvm/llvm-project/pull/106061