This makes the strong link from optimized code to code objects for all
inlined functions explicit. It adds direct references to code objects
into deoptimization data as literals. Note that this is not necessarily
the code that will be deoptimized to, because the code on the shared
function info might be replaced by other components (e.g. debugger).
Those replacement code objects however are all non-flushable, marking
explicit strong links for reachability unnecessary.

R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/1490233009

Cr-Commit-Position: refs/heads/master@{#32654}