[llvm] [llvm-size] Fix --totals option for Mach-O files (PR #157904)

[Ryan Mansfield via llvm-commits]

rjmansfield wrote:

> See #86644. I suspect this fixes the issue (so add the relevant annotation to the PR description, please).

Unfortunately it doesn't. The 4G `__PAGEZERO` segment is still counted as a part of `others`. Since size is meant to report the vmsize, and the zero filled `__PAGEZERO` segment is part of the binary, the number is correct but can be misleading to users with respect to the other sizes. I think in this case a macho specific option that excludes `__PAGEZERO` might provide more reasonable total. I can push up a separate patch for that. 

https://github.com/llvm/llvm-project/pull/157904