Many build scripts, ports and other third-party add-ons that are
circulating around appear to be distributed under the MIT License.
Examples include the Vcpkg build system (including the libpng port)
and the Meson build definitions (including the libpng definition).
I am, therefore, relicensing our CI scripts once more, as the sole
author (so far), just in case that any of the CI code might travel
from/to such projects. Hopefully, this one last license will stick.
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
Rename `CI_HOST_ARCH` and `CI_HOST_SYSTEM`, to `CI_BUILD_ARCH` and
`CI_BUILD_SYSTEM`, following the nomenclature used by GNU Autotools.
Unfortunately, the word "host" has confusingly opposite meanings in
CMake (and Bazel, etc.) vs. Autotools (and Meson, etc.)
Remove `CI_TARGET_TRIPLET` and `CI_TARGET_ABI` (for now).
Introduce the function `ci_expr` as a fast and easy equivalent of
`expr >/dev/null`.
Rephrase the assertions using an implementation pattern that is more
expressive, yet (arguably) just as readable. Remove `ci_assert`.
Modify the main functions to display more useful information in case
of usage error.
