[lld] r248679 - [ELF2/AArch64] Support for R_AARCH64_ADR_PREL_LO21 relocation.

[Rafael Espíndola via llvm-commits]

> +.globl _start
> +_start:
> +  adr x1,msg
> +msg:  .asciz  "Hello, world\n"
> +msgend:
> +
> +// R_AARCH64_ADR_PREL_LO21
> +# CHECK: _start:
> +# CHECK:   11000:       21 00 00 10     adr     x1, #4

Please expand the comment a bit saying why this is the correct value.

A trick being used in other tests is to name the section with the
relocation name.

Cheers,
Rafael