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

[Alastair Houghton via llvm-commits]

al45tair wrote:

This is a cherry-pick of https://github.com/swiftlang/llvm-project/pull/9095.

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