[ObjC declaration documentation] declaration of 
types involving Objective-C pointers must have
their arc qualifiers elided as they don't 
add any additional info. // rdar://13757500.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180860 91177308-0d34-0410-b5e6-96231b3b80d8