Port 32de6778

Original commit message:
The reason is that this information will be needed to compute the number of
vector ic slots done at numbering time.

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

Review URL: https://codereview.chromium.org/1153113002

Cr-Commit-Position: refs/heads/master@{#28633}