More direct emission of instructions.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/abstract_intel_emit@15253 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
RxD 32-bit registers.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/abstract_intel_emit@15254 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Cleanup.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/abstract_intel_emit@15255 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02