Merge topic 'cmake-language-exit-code'

1bb1769235 cmake_language: Add EXIT subcommand
4f160f7906 cmakemain: Return the SCRIPT_MODE exit code if it was set
b62dcbf5d2 cmMakefile: check cmake script mode exit code after command
3d9d504646 cmMakefile: Store the exit code from cmExecutionStatus to cmake instance
9f6c937408 Source/cmake.h: Add ScriptModeExitCode for proper storing exit code
1082b9cb9a cmExecutionStatus: Add ability to set optional custom exit code

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: buildbot <buildbot@kitware.com>
Acked-by: Leonid Pospelov <pospelovlm@yandex.ru>
Acked-by: NoMaY (a user of Renesas Rulz Japanese Forum) <nomay-jp@outlook.com>
Merge-request: !8228