When storing an indexed property in a typed array, it's necessary to
convert the value to a Number (or to a Bigint) before performing the
bounds check, per
https://tc39.github.io/ecma262/#sec-integerindexedelementset.

This CL adds appropriate type conversions in
Object::SetPropertyInternal (which technically is reached after the
bounds check has already occurred, but this isn't observable yet ---
In the future, once OOB accesses on TypedArrays actually throw, this
will need to be refactored again), and in StoreFastElementStub, and
ElementsTransitionAndStoreStub (via CSA::EmitElementStore).

The change was not necessary in TurboFan, as
JSNativeContextSpecialization already performs the value conversion
before the boundscheck.

The result is some fixed test262 tests, and some new test coverage
for this behaviour in mjsunit.

BUG=v8:7896, v8:5327
R=neis@chromium.org, jkummerow@chromium.org, gsathya@chromium.org

Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: Ibe6bec24c72ef6a4fd3e77d5bcafa03737f4c5e3
Reviewed-on: https://chromium-review.googlesource.com/1117372
Commit-Queue: Caitlin Potter <caitp@igalia.com>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54096}