Fixing bug in native compiler with let patterns in fixpoint definitions.
Typical example: Fixpoint f (m : nat) (o := true) (n : nat) {struct n} := n.
Was raising an "index out of bounds" exception at compile-time.
Nota: this construction is still incorrectly handled by the VM.



git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@16197 85f007b7-540e-0410-9357-904b9bb8a0f7