Port a4b19dcc

Original Commit Message:

    This switches from copying entire runtime stubs into each module to only
    having small jump table slots in each module that act as a trampoline to
    the actual embedded builtin representing the runtime stub. This reduces
    the memory footprint of modules.

R=mstarzinger@chromium.org, joransiu@ca.ibm.com, michael_dawson@ca.ibm.com, miladfar@ca.ibm.com
BUG=
LOG=N

Change-Id: Ibbe5fdf4d926b45582748ae8b15eb316107409dc
Reviewed-on: https://chromium-review.googlesource.com/c/1470455Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Junliang Yan <jyan@ca.ibm.com>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#59629}