Remove C-API header generation from build
With our own API in place we can finally remove the build system magic and cpython sourcecode filetering scripts.
- Make the `capi-headers` target simply add `pyro/capi` to the search path.
- `build/Include` is still assembled for distutils and packaging purposes but is not directly used in the build.
- Remove all the cpython header/source generation scripts.
- cpython code uses internal headers that pyro does not provide. This creates `capi/cpython-internal` and symlinks those headers there. Internal headers will no longer be exposed to other parts of the code. Note that putting `third-party/cpython/Include` into the search-path does not work because it means we pick up unwanted headers from that directory as well where we want pyros version to be used instead.
Based on Facebook D19986549
authored by