Export sage.libs.pari.gen.new_ref()

[pjbruin]

In #20241, the Cython methods new_gen() and new_gen_noclear() of sage.libs.pari.pari_instance were made into public Cython functions in the new module sage.libs.pari.stack. The related method new_ref() was made into a private Cython function in sage.libs.pari.gen. We export this function because it is useful for #15601 and possibly elsewhere.

CC: @defeo @jdemeyer

Component: packages: standard

Keywords: pari

Author: Peter Bruin

Branch/Commit: e71808c

Reviewer: Jeroen Demeyer

Issue created by migration from https://trac.sagemath.org/ticket/21755

[pjbruin]

Branch: u/pbruin/21755_export_new_ref

[pjbruin]

Changed author from defeo, jdemeyer to Peter Bruin

[pjbruin]

Commit: e71808c

[jdemeyer]

Reviewer: Jeroen Demeyer

[vbraun]

Changed branch from u/pbruin/21755_export_new_ref to e71808c