Issue #18948: improve SuppressCoreFiles to include Windows crash popup suppression, and use it in more tests.
Patch by Valerie Lambert and Zachary Ware.

Fix macro expansion of _PyErr_OCCURRED(), and make sure to use it in at least one place so as to avoid regressions.

Fix macro expansion of _PyErr_OCCURRED(), and make sure to use it in at least one place so as to avoid regressions.

Ensure that the module is unloaded to be able to run the test more than once,
and to not leak memory.