We fix these Cython warnings either by

1. Removing inline for the declaration in the .pxd file

2. or, not declaring the function in the .pxd file at all (in case the function is never used outside of the module defining it).

Component: cython

Author: Jeroen Demeyer

Branch/Commit: 65abd9d

Reviewer: Vincent Delecroix

Issue created by migration from https://trac.sagemath.org/ticket/23771