This CL replaces the current TypedArray#sort with a simpler mergesort.
The fastpath when the user does not provide a comparison function
is still used.

In addition, TypedArray#sort now converts all elements in the
TypedArray to tagged values upfront, sorts them and writes them
back into the TypedArray as the final step.

R=jgruber@chromium.org, tebbi@chromium.org

Bug: v8:8567
Change-Id: Ib672c5cf510f7c0a2e722d1baa2704305a9ff235
Reviewed-on: https://chromium-review.googlesource.com/c/1445987
Commit-Queue: Simon Zünd <szuend@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Mathias Bynens <mathias@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59271}