- Throw a TypeError exception if a given target argument is not a typed
array before converting a given offset argument to an integer.
- Add a testcase

Bug: chromium:768775
Change-Id: Id132a0f154fcf930f211922fcbef6c66f9d6f285
Reviewed-on: https://chromium-review.googlesource.com/728120Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48736}