[lld] r248056 - [elf2] Relocate against undefined weak symbols.

[Rafael Espíndola via llvm-commits]

> +.global _start
> +_start:
> +  movl $1, sym1(%rip)
> +
> +.weak sym1
> +
> +// CHECK: movl    $1, -69642(%rip)
>

Please expand the description on why -69642 is the correct answer. See
got.s for an example.

Cheers,
Rafael