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

[Piotr Zegar via cfe-commits]

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@@ -0,0 +1,61 @@
+.. title:: clang-tidy - bugprone-pointer-arithmetic-on-polymorphic-object
+
+bugprone-pointer-arithmetic-on-polymorphic-object
+=================================================
+
+Finds pointer arithmetic performed on classes that declare a virtual function.
+
+Pointer arithmetic on polymorphic objects where the pointer's static type is 
+different from its dynamic type is undefined behavior, as the two types can
+have different sizes.
----------------
PiotrZSL wrote:

"as the two types can have different sizes."
this apply also to non polymorphic classes.

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