This constructs different typed arrays from different types of other
typed arrays, hopefully countering microbenchmarks which are able to
optimize for exactly one pair of types.

Bug: v8:5977
Change-Id: Ie3b07d6ecaaca6db0be410e902e437a2a643d71c
Reviewed-on: https://chromium-review.googlesource.com/474748Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44576}