When TypedArray builtin code was still in JS, we used to completely
elide IterableToList when passed an array. This meant that it was
possible for the builtins to observe side-effects which mutated the
array when that should have been impossible.

When IterableToList was ported to CSA, it changed to clone the passed-in
array instead of passing it through. This means that there's now no
need to guard against side-effects due to ToNumber conversions, so we
can simply return the result of Object::IterationHasObservableEffects.

Though no test changes are included here, this code is covered
by the regression tests added previously when this runtime function
was added (and later modified).

This still leaves a future TODO to port IterationHasObservableEffects
to CSA.

Change-Id: If913c035b124ecb59a5f647344b653429a162a2b
Reviewed-on: https://chromium-review.googlesource.com/1159733Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54876}