r220812 - Objective-C. revert patch for rdar://17554063.

[jahanian]

> On Oct 28, 2014, at 12:12 PM, Nico Weber <thakis at chromium.org> wrote:
> 
> Is it possible to give a short motivation in your CL descriptions?
> 

Sure.  This is reverting a new API for Objective-C’s collection literal implementation which had consequences for
users of these literals in that they had to modify their code. We decided that we will replace this with a new approach
in near future which is more efficient (and user will get more performance benefit event though they still have to change their code).

- Fariborz