Indirections for external references are now handled completely in
macro assemblers, which can produce more efficient code.

Bug: v8:6666
Change-Id: I158f2e2517e2d97a1006cec6e3b4ac3a7ef3fab6
Reviewed-on: https://chromium-review.googlesource.com/1095307
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53666}