Enable VerifyHeap and DumpHeap.

Enable VerifyHeap and DumpHeap.

Fix error output. The lldb function cached all the error output separately from the normal output so the error/normal text are not properly intermixed.

Fixed calculation in CardIsSet getting the lowest address from card table header. Use the ALIGN_DOWN macro to make it a little more clear what is going on in CardIsSet.  Couldn't include stdmacros.h (containing this macro) in the sos context so the macro has been copied to the beginning of the file.

Changed some "unsigned long" in sos to "ULONG" because it is different between Linux and Windows.