support for the case where alignment<value size.
These cases were silently miscompiled before this patch.
Now they are overly verbose -especially storing is- and
any front-end should still avoid misaligned memory
accesses as much as possible. The bit juggling algorithm
added here probably has some room for improvement still.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118889 91177308-0d34-0410-b5e6-96231b3b80d8
