Getting rid of Pexp_assertfalse/Texp_assertfalse.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/extension_points@13548 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Get rid of the 'explicit arity' flag on Pexp_construct/Ppat_construct.  If really requires (for camlp5?), the feature should be reimplemented with attributes.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/extension_points@13549 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Check AST invariants.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/extension_points@13550 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02