rust-cpython: add generation counter to leaked reference
This counter increments on borrow_mut() to invalidate existing leaked
references. This is modeled after the iterator invalidation in Python.
The other checks will be adjusted by the subsequent patches.
# See http://EditorConfig.org for the specification
root = true
[*.py]
indent_size = 4
indent_style = space
trim_trailing_whitespace = true
[*.{c,h}]
indent_size = 8
indent_style = tab
trim_trailing_whitespace = true
[*.t]
indent_size = 2
indent_style = space
trim_trailing_whitespace = false