[TS] Preserve fake values in symbolic reference-array reads

[CaelmBleidd]

Problem

Symbolic reference-array reads can lose the fake-value representation when the address region contains a fake wrapper behind a symbolic array read.

A fake value must keep its boolean, number, and reference payloads together with the corresponding discriminators until its runtime kind is proven. Treating the resulting address expression as a plain reference drops the boolean/number alternatives.

Reproduction

class ArrayElement {}

function inputAnyPreservesNumber(values: ArrayElement[], value: any): number {
    if (values.length !== 1) {
        return 0;
    }

    values[0] = value;
    const popped: any = values.pop();

    if (typeof popped === "number") {
        return 44;
    }

    return 0;
}

The path returning 44 must be reachable: assigning any performs no runtime cast, so value may be a number.

Actual behavior

Both the legacy Array.pop approximation and the intrinsic model from #377 produce only the path returning 0.

The non-empty read is represented as an address-sorted symbolic expression similar to:

ite(index == 0, fakeWrapper, inputArray<unknown[]>[index])

This expression is not a concrete fake-wrapper heap reference, so isFakeObject() returns false. Consumers then treat it as a plain reference and can no longer access the boolean/FP64 payloads or discriminator constraints.

Root cause

• Reference-element arrays are normalized to the unknown[] storage descriptor.
• A fake wrapper can be written to that address region.
• Reading the symbolic address region may return a conditional expression containing the wrapper rather than the concrete wrapper itself.
• Current fake-value recognition and extraction handle only a concrete synthetic wrapper reference.

Required behavior

Implement a fake-aware symbolic array read that preserves all supported representations and discriminator constraints, including alias consistency for already materialized fake values.

Until this is implemented, semantic models must not claim symbolic/input reference arrays as a supported domain.

Regression test

PR #377 will include a disabled end-to-end regression test linked to this issue.