The README and the Sphinx requirements page still describe the plugin as
supporting GCC 4.6 or later (tested up to GCC 8) and Python 2.7 or 3.2+.
That support is historical: current GCC releases no longer build the
plugin, and Python 2 is long end-of-life.

Document the maintenance baseline instead: Python 3 is the target, GCC
plugin compatibility is established per GCC release, no current GCC
release is claimed as supported until it has been built and tested, and
x86_64 and ppc64le are the intended test platforms.

README.rst:
* Add a "Maintenance status" section.
* Requirements: replace the GCC 4.6+ and Python 2.7/3.2+ claims.  Note
  that the plugin headers must match the exact GCC version, and that the
  plugin is compiled as C++, so the matching C++ compiler is required.
* Usage: replace the x86_64-only note with the intended test platforms.

docs/basics.rst:
* Requirements: same GCC and Python changes as README.rst.
* Build-time dependencies: drop the Python 2 package list; use dnf and
  add gcc-c++.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

The Makefile defaults to "python" and "python-config".  Many current
distributions provide neither command, and where they exist they may
refer to Python 2 or to an unintended interpreter.

Default to python3 and python3-config instead.  PYTHON and PYTHON_CONFIG
can still be overridden on the make command line.

Makefile:
* Default PYTHON to python3 and PYTHON_CONFIG to python3-config.
* Update the comment describing the defaults, and drop the commented-out
  python3 example, which is now the default.

docs/basics.rst:
* Describe the new default and how to select another Python 3.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.travis.yml targets Travis CI's long-retired Ubuntu Precise/Trusty
images, builds with GCC 4.8 through 9, and installs Python 2 packages.

Replace it with a GitHub Actions workflow.  Following the maintenance
plan, start with one reproducible job rather than a large matrix:
Linux x86_64, Python 3 and a single GCC release, in a pinned
ubuntu:22.04 container.

GCC 11 and later do not build the current sources (checked with GCC 11
through 16), so the job uses GCC 10, the release before those API
changes.  Ubuntu 22.04 provides GCC 10 together with Python 3.10; the
test tooling still relies on distutils and configparser.SafeConfigParser,
which Python 3.12 removed.

The job builds the plugin serially, because the Makefile is not yet safe
for parallel builds, checks that GCC loads the plugin, and runs the
cpybuilder and dejagnu selftests.  The main test suite also runs, but
does not fail the job for now, since some tests are expected to fail
with current Python releases.

Further GCC releases and architectures will be added to the matrix as
their compatibility fixes land.

.travis.yml: Remove.

.github/workflows/ci.yml: New file.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>