rust-cpython: start cpython crate bindings
This changeset introduces the hg-cpython crate,
that compiles as a shared library holding a whole
Python package (mercurial.rustext), with only the empty
'ancestor' submodule for now.
Such bindings will be easier and safer to develop and maintain
that those of `hg-direct-ffi`.
They don't involve C code, only unsafe Rust that's mostly isolated
within the cpython crate.
The long-term goal would be to import the provided modules, such
as rustext.ancestor with mercurial.policy.importmod, same as
we already do with cext modules.
Differential Revision: https://phab.mercurial-scm.org/D5434
# 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