[clang] [Clang] Fix 'counted_by' for nested struct pointers (PR #110497)

[Jan Hendrik Farr via cfe-commits]

Cydox wrote:

So, this doesn't fully work yet. When compiling the kernel it seems like there are cases were `StructBase` is now both an LValue and a pointer. Still investigating.

https://github.com/llvm/llvm-project/pull/110497