This will enable tail call optimization even across inlining. Plus it
might enable some other interesting optimizations as well. In order to
avoid blowing up the generated code, we can still canonicalize the
epilogue in the CodeGenerator, similar to what fullcodegen does.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1215623002

Cr-Commit-Position: refs/heads/master@{#29311}