[IRGen]. Fixes a crash in using Objective-C array  
properties by fixing shouldBindAsLValue to accept arrays
(like record types) because we always manipulate
them in memory. Patch suggested by John MaCall.
// rdar://15610943


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@201428 91177308-0d34-0410-b5e6-96231b3b80d8