tests: Use pre-commit to run some tests in Jenkins

The pre-commit tool is able to run style tests in a reproducible
manner. Run pre-commit from Jenkins.

Change-Id: Ia142a6f3b610410b5767515483b90bc3a09f2407
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/61113
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>

tests/jenkins/presubmit-stage2.sh

@@ -37,6 +37,10 @@
 
 set -e
 
+# Run pre-commit style checks
+PRE_COMMIT_HOME=/tmp/pre-commit-cache pre-commit run \
+               --from-ref HEAD~ --to-ref HEAD
+
 # Use ccache with the default directory for caching
 #XXX Not available in docker image.
 #export PATH="/usr/lib/ccache:$PATH"