p2000: add new commands

Signed-off-by: Derrick Stolee <[email protected]>

Author: derrickstolee

t/perf/p2000-sparse-operations.sh

@@ -110,5 +110,11 @@ test_perf_on_all git add -A
 test_perf_on_all git add .
 test_perf_on_all git commit -a -m A
 test_perf_on_all git checkout -f -
+test_perf_on_all git reset
+test_perf_on_all git reset --hard
+test_perf_on_all git update-index --add --remove
+test_perf_on_all git diff
+test_perf_on_all git diff --staged
+test_perf_on_all git sparse-checkout reapply
 
 test_done