The sort method of TypedArrays sorts in numerical order by default.
This patch implements sorting based on Arrays and adds a test.
The length of %TypedArray%.prototype.sort, like Array.prototype.sort,
seems to be unspecified in ES6, so this patch lets it have the value
1, to match our interpretation for Array.prototype.sort (though 0
would also be a sensible length).

R=arv@chromium.org
BUG=v8:3578
LOG=Y

Review URL: https://codereview.chromium.org/1148513002

Patch from Daniel Ehrenberg <dehrenberg@chromium.org>.

Cr-Commit-Position: refs/heads/master@{#28494}