We want to be able to use this from other builtins as well, so move it
to somewhere common.

Also adds typing and cleans up the coding style to match newer CSA code
a bit more. GrowableFixedArray is now a subclass of CodeStubAssembler
to make things easier and cleaner. The growing strategy has also been
slightly changed so that empty arrays can be produced.

Change-Id: I20cbd1069d489a6875804736d3e5abab80d0f777
Reviewed-on: https://chromium-review.googlesource.com/901324Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51107}