[compiler-rt] [llvm] [ORC][MachO] Use a per-graph compact-unwind dso_base (PR #208931)

[Lang Hames via llvm-commits]

lhames wrote:

Thanks again for your patience with this @cyx-6!

Short term, how would you feel about switching to the slab based `MapperJITLinkMemoryManager` on Darwin (and potentially Linux too)? The slab size is configurable, but I think it'd make sense to just leave it high (e.g. 1Gb) -- address space is cheap, and you don't pay for the memory unless you actually use it.

If you do want to enable island-based MachOs I think we'd need to do some more design work to make it optional, rather than always-on.

https://github.com/llvm/llvm-project/pull/208931