This simplifies correlating offsets with the output from
--print-opt-code, which outputs offsets in decimal.

We keep the hex output since branch instructions in the perf dump use
hex labels. We just include the decimal offset along with the hex offset.

BUG=

Review URL: https://codereview.chromium.org/1612403002

Cr-Commit-Position: refs/heads/master@{#33455}