Fixing #3062. Computation of the value of a fresh identifier was
done too early and lead to dynamic conflicts.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@16660 85f007b7-540e-0410-9357-904b9bb8a0f7
Added a test for bug #3062.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@16661 85f007b7-540e-0410-9357-904b9bb8a0f7