Refactor for object source files variable in Makefile

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2020-08-28.18:58:28.163>
labels = ['type-feature', 'build']
title = 'Refactor for object source files variable in Makefile'
updated_at = <Date 2020-08-28.19:57:22.774>
user = 'https://github.com/ElianMariano'

bugs.python.org fields:

activity = <Date 2020-08-28.19:57:22.774>
actor = 'ElianMariano'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Build']
creation = <Date 2020-08-28.18:58:28.163>
creator = 'ElianMariano'
dependencies = []
files = []
hgrepos = []
issue_num = 41657
keywords = ['patch']
message_count = 1.0
messages = ['376045']
nosy_count = 1.0
nosy_names = ['ElianMariano']
pr_nums = ['21993']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue41657'
versions = []