PPC: Speed up cctest/test-debug/DebugBreakLoop.
PPC: Speed up cctest/test-debug/DebugBreakLoop.

Port a67f31c48c7bb7a3f653e32e0a48143099d27b68

R=yangguo@chromium.org, michael_dawson@ca.ibm.com, jyan@ca.ibm.com, joransiu@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1263863003

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#29940}

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh