[AMD] Dynamic local resource assignment based on thread ID is always 0

@tcorringham is already working on this.

Since Jul 28, 2026.

In this shader:
```
RWByteAddressBuffer gBufArray[4] : register(u0);

[numthreads(4,1,1)]
void main(uint3 tid : SV_DispatchThreadID) {
RWByteAddressBuffer buf = gBufArray[tid.x];
buf.Store(0, 42);
}
```
gBufArray is always indexed at 0, when the index should range from 0-3 depending on the executing lane.
The result is that the output array's first buffer has 42 at pos 0, but the other 3 buffers start with 0.
We should expect all buffers within gBufArray to have a 42 at pos 0.

The same behavior manifests in this shader as well:
```
RWByteAddressBuffer gBufArray[4] : register(u0);

[numthreads(4,1,1)]
void main(uint3 tid : SV_DispatchThreadID) {
RWByteAddressBuffer arr[4];
arr[0] = gBufArray[0];
arr[1] = gBufArray[1];
arr[2] = gBufArray[2];
arr[3] = gBufArray[3];
arr[tid.x].Store(0, 42);
}
```
Only arr[0] has 42 at pos 0, the rest should, but don't.