[clang-tools-extra] [clang-tidy] Improve sizeof(pointer) handling in bugprone-sizeof-expression (PR #94356)

[Donát Nagy via cfe-commits]

NagyDonat wrote:

Minor correction: in the commit message I accidentally wrote `alpha.core.SizeofPointer` instead of `alpha.core.SizeofPtr`. (Fortunately this difference is mostly academical, because my followup commit will remove that checker.)

https://github.com/llvm/llvm-project/pull/94356