Unify the constructors and isView methods for ArrayBuffer and
SharedArrayBuffer, moving them to C++ because there's no point
in having the JavaScript wrappers for them.

We choose to deliberately violate the ES2015 specification and
implement the ArrayBuffer constructor in a way that matches
Firefox and Safari instead.

CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel
BUG=chromium:565917, v8:4592
TBR=hpayer@chromium.org
R=cbruni@chromium.org
LOG=n

Committed: https://crrev.com/3235ccbb7826ceec2188f6ebab98fc851b54f60e
Cr-Commit-Position: refs/heads/master@{#32590}

Review URL: https://codereview.chromium.org/1500543002

Cr-Commit-Position: refs/heads/master@{#33072}