The disassembly output recently changed to output pc offsets in hex
(see https://codereview.chromium.org/2757263002).
This CL also changes source positions, safepoints and back edges to use
the same format. This allows easier matching.

R=leszeks@chromium.org, yangguo@chromium.org

Review-Url: https://codereview.chromium.org/2788513004
Cr-Commit-Position: refs/heads/master@{#44294}