[clang] [Clang] Disable use of the counted_by attribute for whole struct pointers (PR #112636)

[Bill Wendling via cfe-commits]

bwendling wrote:

I think the calculation in https://github.com/llvm/llvm-project/pull/112636#issuecomment-2436559387 is correct. It's probably worthwhile to perform some analysis to see if using that to calculate the new size results in allocation size changes in the kernel. If not, then perhaps we could reinstate the "whole struct" code.

https://github.com/llvm/llvm-project/pull/112636