Make a nogil version of the most important methods of FaceIterator.

[kliem]

We outsource 3 crucial methods of FaceIterator to nogil functions.

This is part of #28893: Parallel f-vector for polyhedra.

Anything happening within prange should be without gil. Any function that is called in the parallel section needs to be nogil.

Depends on #28894
Depends on #29654

CC: @jplab @LaisRast @tscrim

Component: geometry

Keywords: polytopes, f-vector

Author: Jonathan Kliem

Branch/Commit: 81372b6

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/29676

[kliem]

Branch: public/29676

[kliem]

Author: Jonathan Kliem

[kliem]

Commit: c6fe6d4

[kliem]

New commits:

0c44221	important attributes of iterator in structure
efb0bd3	src/simplification of doctests
53fd2a2	fixed failing doctest
c6fe6d4	make nogil function of crucial methods in FaceIterator

[jplab]

comment:2

Could you extend a little bit in the description on what this does?

[kliem]

Description changed:

--- 
+++ 
@@ -1,3 +1,5 @@
 We outsource 3 crucial methods of `FaceIterator` to nogil functions.
 
 This is part of #28893: Parallel f-vector for polyhedra.
+
+Anything happening within `prange` should be without gil. Any function that is called in the parallel section needs to be nogil.

[tscrim]

comment:6

Shouldn't you also make the corresponding changes/additions to the pxd file?

[kliem]

Changed commit from c6fe6d4 to 81f43ea

[kliem]

Changed branch from public/29676 to public/29676-reb

[kliem]

New commits:

9045767	make nogil function of crucial methods in FaceIterator
81f43ea	expose nogil functions in header