[7.6] Fix data structure size mismatch for instruction recording.

Upstream bug filed at
http://sourceware.org/bugzilla/show_bug.cgi?id=15518

With this patch reverse debugging is working in ARM mode.

Change-Id: I488262b50eef85e0c2447a3a31551ea95a0409d9

Author: Ben Cheng <bccheng@google.com>
Date:   Wed May 22 13:43:37 2013 -0700