Initialize the arch-specific MSYSTEM environment variable, to ensure
that msys2 bash picks up and executes /etc/profile correctly.
Install and use the host-specific cmake and ninja, to ensure that
msys2 cmake picks up the host-specific zlib build correctly.
Update the Travis CI matrix:
* Run ASan and UBSan unconditionally on FreeBSD and Linux, and
not at all on Mac.
* Remove the `CI_NO_TEST=1` runs from the environment column.
Update the AppVeyor CI matrix:
* Replace `CI_NO_TEST=1` with `CI_CMAKE_VARS=-DPNG_TESTS=0` when
testing Visual Studio on ARM64.
Also apply minor stylistic changes.
Give the CI scripts new names that better reflect what they do, and
make room for activities such as linting or dependency installation:
* Rename ci_autotools.sh to ci_verify_configure.sh.
* Rename ci_cmake.sh to ci_verify_cmake.sh.
* Rename ci_legacy.sh to ci_verify_makefiles.sh.
Also rename CI_LEGACY_MAKEFILES to CI_MAKEFILES.
Update the config files for Travis CI and AppVeyor CI accordingly.
Apply the following changes:
* Add FreeBSD (besides Linux and Mac) to the Travis CI testing.
* Use cc instead of clang for Xcode in the Travis CI testing.
* Upgrade the Windows test image from Visual Studio 2019 to
Visual Studio 2022 for AppVeyor CI.
Update the ci_*.sh scripts and move them to the more conventional
ci/ directory. Update .appveyor.yml and .travis.yml, as well as
the AUTHORS file, accordingly.
Speed up ci_cmake.sh: add "-DPNG_TESTS=OFF" to the list of CMake
variables if CI_NO_TEST is true.
Remove "sudo: false" from .travis.yml.
Refactor .appveyor.yml.
Exclude the branch "libpng16" from testing. It's identical to "master".
Also exclude the other (non-current) "libpng[0-1][0-7]" branches.
Parallelize the builds and the unit tests.
For Travis CI, update the build matrix as follows:
* On Linux, use both clang and gcc.
* On macOS, use clang only, with and without Xcode.
For AppVeyor CI, add a build matrix as follows:
* On Windows, use Microsoft Visual Studio 2019 on x86, x64 and arm64.
* Also on Windows, use MSYS2 on x86 and x64.
Use the new scripts/ci_*.sh; remove the old scripts/travis.sh.
