Add support for S390 to GDB-JIT.

R=danno@chromium.org,jkummerow@chromium.org,jochen@chromium.org,jyan@ca.ibm.com,michael_dawson@ca.ibm.com,mbrandy@us.ibm.com

BUG=

Review URL: https://codereview.chromium.org/1804193002

Cr-Commit-Position: refs/heads/master@{#34800}