git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1354 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e

- Revised memory model with concrete representation of ints & floats,
  and per-byte access permissions
- Revised Globalenvs implementation
- Matching changes in all languages and proofs.


git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1282 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e