Shu-yu Guo

`AllocateTypedArray` can either have steps 1-6 refactored out, or inlined in step 6.b of the [TypedArray constructor](https://tc39.es/ecma262/multipage/indexed-collections.html#sec-typedarray), and then the whole of step 6.b itself refactored out into its own...

For ValidateAtomicAccessOnIntegerTypedArray, we should remove the waitable parameter and refactor the one callsite in Atomics.notify that passes true for the parameter.

Indeed, the global integer (modulo some overflow handling complexity that's not needed in the spec) is how V8 implements that logic anyhow.