Editorial: Align checks order in [[DefineOwnProperty]] overrides with ordinary method

[shvaikalesh]

With the current spec, if an engine precisely implements ValidateAndApplyPropertyDescriptor and module namespace object's [[DefineOwnProperty]] method, with descriptive error message for each failure, it would report different errors (given there is > 1 cause of failure) for the same (CurrentDescriptor, Descriptor) pair when called on ordinary object vs module namespace object.

Test case:

module.js:

export let test = 42;

index.js:

import("module.js").then(ns => {
    const desc = { get() {}, configurable: true };
    Object.defineProperty(ns, "test", desc); // => TypeError: Cannot change module namespace object's binding to accessor
    const plain = {};
    Object.defineProperty(plain, "test", Object.getOwnPropertyDescriptor(ns, "test"));
    Object.defineProperty(plain, "test", desc); // => TypeError: Attempting to change configurable attribute of unconfigurable property.
});

---

This change aligns descriptor validation order of TypedArray's and module namespace object's [[DefineOwnProperty]] methods with ValidateAndApplyPropertyDescriptor. For own non-configurable data descriptor, that is [[Configurable]] => [[Enumerable]] => IsAccessorDescriptor => [[Writable]] => [[Value]].

The discrepancy this PR fixes is currently observable only in JSC.

[bakkot]

I'm neutral on this change, but it seems fine.

[ljharb]

i agree that the order of these steps is unobservable