More array casting work:

- Continue adding support for checked downcasts of array types (rdar://problem/16535104)
- Fix non-bridged array conversions post-r17868
- Fix rdar://problem/16773693
- Add tests for NSArray coercions to and from Array<T>

Swift SVN r17957

lib/Sema/ConstraintSystem.cpp

@@ -650,7 +650,6 @@ Type ConstraintSystem::openType(
 }
 
 bool ConstraintSystem::isArrayType(Type t) {
-  
   // ArraySliceType<T> desugars to Array<T>.
   if (isa<ArraySliceType>(t.getPointer()))
     return true;