Fix a bug where when debugging with .o files, we end up with two symbols for...

Fix a bug where when debugging with .o files, we end up with two symbols for each real OBJC_CLASS_$_whatever, one of which is correctly classified as an ObjCClass symbol, and the other is just a data symbol.  This was messing up the ObjC dynamic type detection.
<rdar://problem/10589527>

llvm-svn: 146712