A -ppx rewriter to evaluate expressions at compile time.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/extension_points@13506 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Comments.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/extension_points@13507 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Convenience functions to build AST + implicit location.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/extension_points@13508 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Continue convenience functions.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/extension_points@13509 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02