Add logic to the ObjC runtime in LLDB to extract the pointer values of the two...

Add logic to the ObjC runtime in LLDB to extract the pointer values of the two singleton (pairtons?) instances of __NSCFBoolean that represent true and false

This is useful because that knowledge will in turn allow no-code-running formatting of boolean NSNumbers; but that's a commit that will have to wait Monday..

llvm-svn: 279353