[PATCH] Fix crashes when creating global instances of polymorphic classes without fields

[Timur Iskhodzhanov]

  FTR at ToT, the crashes happen when calling
    CGF.registerGlobalDtorWithAtExit(D, dtor, addr);
  later in
    ItaniumCXXABI::registerGlobalDtor
  or
    CGCXXABI::registerGlobalDtor

http://llvm-reviews.chandlerc.com/D1795