Thread Safety Analysis:  Replace the old and broken SExpr with the new
til::SExpr.  This is a large patch, with many small changes to pretty printing
and expression lowering to make the new SExpr representation equivalent in
functionality to the old.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@214089 91177308-0d34-0410-b5e6-96231b3b80d8
Objective-C. Improve diagnostic when property is
not auto synthesized in current implementation.
rdar://17774815


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@214090 91177308-0d34-0410-b5e6-96231b3b80d8