[clang-tools-extra] [clang-tidy] Add `bugprone-pointer-arithmetic-on-polymorphic-object` check (PR #91951)

[Piotr Zegar via cfe-commits]

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@@ -126,6 +126,11 @@ New checks
   reference. This may cause use-after-free errors if the caller uses xvalues as
   arguments.
 
+- New :doc:`bugprone-pointer-arithmetic-on-polymorphic-object
+  <clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object>` check.
+
+  Finds pointer arithmetic performed on classes that declare a virtual function.
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PiotrZSL wrote:

Change this description to point about polymorphic-object. Or instead of that declare (class does not declare anything), just say "that contain".

https://github.com/llvm/llvm-project/pull/91951