Revert r184205 and associated patches while investigating issue with broken buildbot (possible interaction with LTO)

<rdar://problem/14209661>

llvm-svn: 184384

clang/lib/CodeGen/CodeGenFunction.h

@@ -798,6 +798,10 @@ private:
   CGDebugInfo *DebugInfo;
   bool DisableDebugInfo;
 
+  /// If the current function returns 'this', use the field to keep track of
+  /// the callee that returns 'this'.
+  llvm::Value *CalleeWithThisReturn;
+
   /// DidCallStackSave - Whether llvm.stacksave has been called. Used to avoid
   /// calling llvm.stacksave for multiple VLAs in the same scope.
   bool DidCallStackSave;