FetchContent is now disabled by default, when the project is included as
an subproject by another top-level project.
Also, every usage of FetchContent is behind a separate flag to enable and
disable the usage with granular control.
- Remove nested minimum required to supress warnings.
- Declare SystemC as system library to supress warnings in headers.
- Add a BUILD_SHARED_LIBS option
- Remove hardcoded STATIC in various add_library calls to honor the
BUILD_SHARED_LIBS option
- Remove _deps/ directory from the build directory in GitLab pipeline
- Remove *.tdb files after test stage in pipeline
- Set Ninja as the default generator for the dev preset and re-enable
colored diagnostics
