[PATCH] Remove copies of MCSubtargetInfo from MCRelaxableFragment

[Duncan P. N. Exon Smith]

> On 2015-Jul-10, at 11:54, Rafael Espíndola <rafael.espindola at gmail.com> wrote:
> 
>> So I guess it's probably worth untangling this further.  I could convert
>> everything `encodeInstruction()` calls transitively to take a
>> `FeatureBitset` instead of a `const MCSubtargetInfo &`.  Make sense?
> 
> BTW, it wouldn't surprise me if you could just pass the fragment
> itself and store just a few booleans in it (IsMicroMips, IsThumb,
> etc).

Although that would expose more of the implementation details Eric
wants to avoid...  I'm inclined to just push the feature bits through.