[llvm] r255902 - Avoid explicit relocation sorting most of the time.

[Rafael Espíndola via llvm-commits]

>> +static int cmpRel(const ELFRelocationEntry *AP, const ELFRelocationEntry
>> *BP) {
>> +  const ELFRelocationEntry &A = *AP;
>> +  const ELFRelocationEntry &B = *BP;
>> +  if (A.Offset != B.Offset)
>> +    return B.Offset - A.Offset;
>> +  if (B.Type != A.Type)
>> +    return A.Type - B.Type;
>> +  return 0;
>
>
> This dropped the unreachable present in the prior version (which I just
> commented on as well) - intentionally?
>

It was, sorry for taking so long to reply, I missed this before going
on vacations.

The story of that function is

* We use to have some non determinism on the order relocations were
created (walking a map/set of pointer?)
* We started sorting to make it deterministic.
* We got a target hook to implement mips craziness.
* At some point the non determinism was fixed.
* With this patch the function is now just part of the mips implementation.

My thinking was that it was then OK for two relocations to compare
equal, since they were created in a deterministic order. I now see
that that thinking is bogus since different qsort implementations
would produce different results. r257796 uses the assert you
suggested.

Thanks,
Rafael