[lld] [lld/ELF] Place large executable sections at the beginning (PR #70358)

[Fangrui Song via llvm-commits]

MaskRay wrote:

I think we can give this a try. Best to mention when LLVM started to emit `.ltext` for large code model. #70358 ? 

The code and x86-64-section-layout.s has other changes, so this PR needs a rebase. We probably should add another assembly file in `x86-64-section-layout.s` for `.ltext` with very few other sections.

https://github.com/llvm/llvm-project/pull/70358