[llvm-objdump] Decrease instruction indentation for non-x86

Place the instruction at the 24th column (0-based indexing), matching
GNU objdump ARM/AArch64/powerpc/etc when the address is low.

This is beneficial for non-x86 targets which have short instruction
lengths.

```
// GNU objdump AArch64
   0:   91001062        add     x2, x3, #0x4
  400078:       91001062        add     x2, x3, #0x4
// llvm-objdump, with this patch
       0: 62 10 00 91   add     x2, x3, #4
  400078: 62 10 00 91   add     x2, x3, #4
// llvm-objdump, if we change to print a word instead of bytes in the future
       0: 91001062      add     x2, x3, #4
  400078: 91001062      add     x2, x3, #4

// GNU objdump Thumb
   0:   bf00            nop

// GNU objdump Power ISA 3.1 64-bit instruction
// 0:   00 00 10 04     plwa    r3,0
// 4:   00 00 60 a4
```

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D81590