PPC: Vector ICs: debugger should save registers for vector store ics.
PPC: Vector ICs: debugger should save registers for vector store ics.

Port bd32a9f711cb14c2b7c34512d43e78bd24960124

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

Review URL: https://codereview.chromium.org/1169763003

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#28847}

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