This adds the Python files in the tests/ directory to be formatted with
./tools/codeformat.py. The basics/ subdirectory is excluded for now so we
aren't changing too much at once.
In a few places `# fmt: off`/`# fmt: on` was used where the code had
special formatting for readability or where the test was actually testing
the specific formatting.
For the sake of older versions of gcc (and other compilers), don't use
the #warning CPP directive, nor the -Wno-error=cpp option.
Also, fix a strict alias warning in modffi.c for older compilers, and
add a test for ffi module.
Addresses issue #847.
David Lechner
Paul Sokolovsky
Damien George
blmorris