port c5dd553c (r29929).

original commit message:

    Adds interpreter entry and exit trampoline builtins. Also implements the
    Return bytecode handler and fixes a few bugs in InterpreterAssembler
    highlighted by running on other architectures.

BUG=

Review URL: https://codereview.chromium.org/1271433002

Cr-Commit-Position: refs/heads/master@{#29943}