[llvm] [Object][x86-64] Add support for `R_X86_64_GLOB_DAT` relocations. (PR #103029)

[Lang Hames via llvm-commits]

lhames wrote:

> Dynamic relocation handling is completely different.

Not at the level being presented here -- this is just computing relocation expressions. I guess what you mean is that dynamic expressions can depend on parameters not available in the existing `RelocationResolver` interface, e.g. `B` and `GOT`?

The document you linked states:
> A dynamic linker need only process dynamic relocations; a static linker must handle any defined relocation.

At least as far as that doc is concerned `RelocationResolver` should probably handle this. ;)

If you want to revert while we discuss I'm fine with that. I think the discussion will depend on how many of these the Swift folks expect they'll need. If this is a one off it's fine to ask clients to handle it. If it turns out that they really need a generic relocation resolver then we can discuss what it should look like.  

https://github.com/llvm/llvm-project/pull/103029