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

[Fangrui Song via llvm-commits]

MaskRay wrote:

Dynamic relocation handling is completely different. It's odd to see a routine doesn't even support RELATIVE, and GLOB_DAG is supported without JUMP_SLOT. The current interface just doesn't have sufficient information for proper dynamic relocation handling.

I strongly believe GLOB_DAT handling should be addressed separately, not in RelocationResolver.

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