[llvm] [yaml2obj] Apply output size limit to Mach-O (PR #210027)

[via llvm-commits]

AI-Risk-Management wrote:

Hi James, understood, and I do not want to create review noise. This patch addresses the Mach-O `MaxSize` validation gap visible after #209695. I built `yaml2obj`, ran the new regression test and all 47 existing Mach-O tests, and included the required AI-assistance disclosure.

Could you clarify whether the concern is the unsolicited scope, the implementation direction, or the contribution process? If the project considers the gap worth fixing and provides a preferred direction, I would be happy to revise the patch. Otherwise, I will leave the PR closed.

https://github.com/llvm/llvm-project/pull/210027