Instead of calculating the OSR entry point both in the bytecode analysis
and in the bytecode graph builder, calculate it once in the analysis and
use that calculation in the graph builder.

Old TODO from https://codereview.chromium.org/2558093005.

Change-Id: I071bc622beb55dc5eddaee25ef28e21fc4b477f0
Reviewed-on: https://chromium-review.googlesource.com/485899
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44888}