[Checkins] [zopefoundation/BTrees] 790bbd: Another pass at fixing the overflow tests on Windows.

[Jason Madden]

  Branch: refs/heads/reduce-boilerplate
  Home:   https://github.com/zopefoundation/BTrees
  Commit: 790bbd8ab9db0909832de001a182811d4df03980
      https://github.com/zopefoundation/BTrees/commit/790bbd8ab9db0909832de001a182811d4df03980
  Author: Jason Madden <jamadden at gmail.com>
  Date:   2020-02-27 (Thu, 27 Feb 2020)

  Changed paths:
    M BTrees/tests/common.py

  Log Message:
  -----------
  Another pass at fixing the overflow tests on Windows.

Also speed up test_internal_keys_after_deletion by 10x by avoiding most calls to __getstate__.