Add two Cython fixes

[jdemeyer]

See:

• Replace "int(val) == 0" by "not val" for gdb.Value instances cython/cython#1439 (merged; fixes corrupted Cython tracebacks with cysignals)
• Fix overriding of cdef by cpdef method in .pxd file cython/cython#545 (merged; needed by Move coercion to Element #20767)

Upstream: Fixed upstream, but not in a stable release.

CC: @robertwb

Component: packages: standard

Author: Jeroen Demeyer

Branch/Commit: 24bc354

Reviewer: Nicolas M. Thiéry

Issue created by migration from https://trac.sagemath.org/ticket/21126

[jdemeyer]

Branch: u/jdemeyer/add_a_cython_fix_for_cpdef_methods

[jdemeyer]

Commit: 093395e

[jdemeyer]

New commits:

093395e

Add a Cython fix for cpdef methods

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

aa02833

Fix Cython gdb debugging

[sagetrac-git]

Changed commit from 093395e to aa02833

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

24bc354

Fix Cython gdb debugging

[sagetrac-git]

Changed commit from aa02833 to 24bc354

[nthiery]

comment:10

+1 on merging this as soon as Cython' PR #545 is merged. I did a ping on this PR.

[nthiery]

comment:11

Robert just merged the PR. So positive review!

Thanks Robert :-)

[nthiery]

Changed upstream from Reported upstream. No feedback yet. to Fixed upstream, but not in a stable release.

[nthiery]

Reviewer: Nicolas M. Thiéry

[vbraun]

Changed branch from u/jdemeyer/add_a_cython_fix_for_cpdef_methods to 24bc354