[lld] [LLD] Implement --enable-non-contiguous-regions (PR #90007)

[Peter Smith via llvm-commits]

https://github.com/smithp35 approved this pull request.

Thanks for the updated tests. I've checked that with a slightly different .ARM.exidx (changing to r7 rather than r8), this isn't prematurely compressed in the first pass.

Given MaskRay's comment in https://discourse.llvm.org/t/rfc-lld-enable-non-contiguous-regions/76513/17 it will be worth running this past him first before merging.

https://github.com/llvm/llvm-project/pull/90007