[lld] [ELF] Set sh_entsize of .{init, fini, preinit}_array to the word size (PR #226697)

[Fangrui Song via llvm-commits]

MaskRay wrote:

If we want parity with GNU, the change belongs to the LLVM integrated assembler (LLVMMC). See  https://github.com/llvm/llvm-project/pull/226875

https://github.com/llvm/llvm-project/pull/226697