Log Message:
meson: updated to 0.56.0

0.56.0:
* meson test can now filter tests by subproject
* Native (build machine) compilers not always required by project()
* New extra_files key in target introspection
* Preliminary AIX support
* Wraps from subprojects are automatically promoted
* meson.build_root() and meson.source_root() are deprecated
* dep.as_link_whole()
* Add support for all Windows subsystem types
* Added NVidia HPC SDK compilers
* Project and built-in options can be set in native or cross files
* unstable-keyval is now stable keyval
* CMake subproject cross compilation support
* Machine file keys are stored case sensitive
* Consistency between declare_dependency() and pkgconfig.generate() variables
* Qt5 compile_translations now supports qresource preprocessing
* Controlling subproject dependencies with dependency(allow_fallback: ...)
* Custom standard library
* Improvements for the builtin curses dependency
* HDF5 dependency improvements
* External projects
* Per subproject warning_level option
* meson subprojects command
* Added CompCert C compiler
* Dependencies listed in test and benchmark introspection
* include_type support for the CMake subproject object dependency method
* Deprecate Dependency.get_pkgconfig_variable and Dependency.get_configtool_variable