cmake HAVE_UNCOMMITTED_CHANGES examples

rcornwell/sims cmake/git-commit-id.cmake :21

execute_process(COMMAND ${GIT_COMMAND} "update-index" "--refresh" "--"
        WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
        RESULT_VARIABLE HAVE_UNCOMMITTED_CHANGES
        OUTPUT_VARIABLE SIMH_UNCOMMITTED_CHANGES)