[lld] [lld/ELF] Place .lrodata at the very end of the binary (PR #81202)

[Fangrui Song via llvm-commits]

MaskRay wrote:

I am actually working on a very similar patch: https://github.com/MaskRay/llvm-project/commits/lld-lrodata/

I have thought about .bss/.ldata/.lbss/.lrodata, but then I feel that we could just the BFD-style .bss/.lbss/.lrodata/.ldata layout.
My patch additionally considers two things:

* `_edata`
* Only set PF_X for the first PF_R PT_LOAD when `--no-rosegment` is specified.

https://github.com/llvm/llvm-project/pull/81202