Port 4598d913

Original commit message:

    This fixes the self-healing mechanism for closures in the interpreter
    entry trampoline not that bytecode can be preserved even when baseline
    code is already available.

R=mstarzinger@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com, mbrandy@us.ibm.com

BUG=chromium:638225
LOG=N

Review-Url: https://codereview.chromium.org/2265193002
Cr-Commit-Position: refs/heads/master@{#38799}