RAB: Integrate staging tests for the .slice method

[ioannad]

of Array.prototype and TypedArray.prototype

This is part of PR #3888 to make reviewing easier. Includes changes to use the helper ./harness/resizableArrayBufferUtils.js

[ptomato]

Should we also have coerced-start-shrink.js for the Array.prototype.slice?

We could also consider testing resizing during coercion of the end argument. Currently these tests only test what happens when coercion of the start argument resizes the buffer.

[ioannad]

Should we also have coerced-start-shrink.js for the Array.prototype.slice?

We could also consider testing resizing during coercion of the end argument. Currently these tests only test what happens when coercion of the start argument resizes the buffer.

@ptomato I added the tests you suggested, and an additional resizable-buffer.js test file for Array.p.slice.

[ptomato]

Thanks!