[llvm] [Dexter] Extend XFAIL of Dexter tests to all MacOS architectures. (PR #83936)

[Jonas Devlieghere via llvm-commits]

JDevlieghere wrote:

We run the debug info tests on GreenDragon on an Intel machine, so if they're not currently XFAIL'd they should be passing there (I'd double check but green.lab.llvm.org is having trouble currently). That said, if they're already disabled on arm I don't mind extending this to x86. 

https://github.com/llvm/llvm-project/pull/83936