This CL implements the SLBR, subtract logical 32-bit int with borrow, instruction in the s390 simulator.

R=michael_dawson@ca.ibm.com,jyan@ca.ibm.com,mbrandy@us.ibm.com,joransiu@ca.ibm.com,

BUG=

Review URL: https://codereview.chromium.org/1850163004

Cr-Commit-Position: refs/heads/master@{#35211}