Identify validation fails to read the index of prefixed opcodes, and not
continue to decode the next bytes.

Change-Id: I2c737af55615ba69ba0c5f5adf18a06c6cdb951a
Bug: chromium:905815
Reviewed-on: https://chromium-review.googlesource.com/c/1390927
Commit-Queue: Deepti Gandluri <gdeepti@chromium.org>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58485}