Previous changes with subclassable builtins and @@species were a bit
aggressive in making TypedArray.prototype.subarray act like the
ES2016 specification in terms of returning an instance of the
subclass as a result. It turns out that Node.js, and extracted
libraries for the web, subclass TypedArrays but don't expect the
subclass constructor to be called by subarray. @@species will provide
an escape hatch, but it has not shipped yet, and will take some time
for uptake by libraries.
For now, this patch makes TypedArray.prototype.subarray fall back to
constructing an instance of the parent TypedArray class, such as
Uint8Array.
R=adamk
LOG=Y
BUG=v8:4665
Review URL: https://codereview.chromium.org/1583773005
Cr-Commit-Position: refs/heads/master@{#33312}
