cmake HAVE_GIT_COMMIT_TIME examples

rcornwell/sims cmake/git-commit-id.cmake :16 

execute_process(COMMAND ${GIT_COMMAND} "log" "-1" "--pretty=%aI"
        WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
        RESULT_VARIABLE HAVE_GIT_COMMIT_TIME
        OUTPUT_VARIABLE SIMH_GIT_COMMIT_TIME)