Merge topic 'exe-check'

8d48d755f0 Tests: Add missing execute_process result checks
a1b5c0da87 Modules: Tolerate CMAKE_EXECUTE_PROCESS_COMMAND_ERROR_IS_FATAL
6b4432bc10 FindGit: Tolerate CMAKE_EXECUTE_PROCESS_COMMAND_ERROR_IS_FATAL

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !12011