[lld] [llvm] [lld][MachO] Follow-up to use madvise() for threaded file page-in. (PR #157917)

[John Holdsworth via llvm-commits]

johnno1962 wrote:

@drodriguez, are we in a position to merge this? It's definitely better than the code related to this feature currently on main the only reservation being changing the buffers to not be null terminated (which you verified for me ‒ thanks!) I've reversed all my other experiments that might have been more speculative.

https://github.com/llvm/llvm-project/pull/157917