[issue37842] Initialize Py_buffer variables more efficiently

Change by Sergey Fedoseev : -- keywords: +patch pull_requests: +14975 stage: -> patch review pull_request: https://github.com/python/cpython/pull/15254 ___ Python tracker ___

[issue37842] Initialize Py_buffer variables more efficiently

New submission from Sergey Fedoseev : Argument Clinic generates `{NULL, NULL}` initializer for Py_buffer variables. Such initializer zeroes all Py_buffer members, but as I understand only `obj` and `buf` members are really had to be initialized. Avoiding unneeded initialization provides tiny