Remove aliases for conditions.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/abstract_intel_emit@15337 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Document that X-only directives can only be used with the X-emitter.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/abstract_intel_emit@15338 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Comments, cleanup.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/abstract_intel_emit@15339 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02