Port 9502e91a

Original commit message:
This allows you to put iterables into your array literals
and the will get spread into the array.

  let x = [0, ...range(1, 3)];  // [0, 1, 2]

This is done by treating the array literal up to the first
spread element as usual, including using a boiler plate
array, and then appending the remaining expressions and rest
expressions.

R=arv@chromium.org, dstence@us.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1149873005

Cr-Commit-Position: refs/heads/master@{#28560}