PPC: Fix 'Remove materialized objects on stack unwind.'
PPC: Fix 'Remove materialized objects on stack unwind.'

R=mstarzinger@chromium.org, jarin@chromium.org, dstence@us.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1123793002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#28209}

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