[PATCH] Fixing a struct layout bug involving a packed derived class with an unpacked non-virtual base

[Reid Kleckner]

  Warren is currently rewriting CGRecordLayoutBuilder so it doesn't duplicate so much of the logic of RecordLayoutBuilder.

  This seems like a fine point fix to add in the mean time, mostly so we can commit the test case.

http://llvm-reviews.chandlerc.com/D2599