Erroneous gradients warning when indexing to an array of textures

Description
Getting the following warning which I think it's incorrect warning: Gradient operations are not affected by wave-sensitive data or control flow. [-Winline-asm]

Steps to Reproduce
Following was built with -T ps_6_6 -E PSMain

struct PSInput
{
    nointerpolation int dynamicallyUniformIndex : IDX; // Same value for the whole drawcall
    float2 uv : UV;
};

Texture2D texes[100];
SamplerState sam;

float4 PSMain(PSInput input) : SV_Target0
{
    int idx = WaveReadLaneFirst(input.dynamicallyUniformIndex); // Scalarize
    float4 val = texes[idx].Sample(sam, input.uv);
    return val;
}

Actual Behavior
The idx is used to select a texture and it shouldn't affect the gradients. I don't think the warning is correct.

Environment

• DXC version: DXC trunk & 1.8.2403
• Host Operating System: Any

Start by reproducing the supplied PSMain example with DXC using -T ps_6_6 -E PSMain and compare the warning on trunk and version 1.8.2403. Trace how the compiler handles WaveReadLaneFirst before the indexed texture Sample; done means the warning is either removed for this case or its behavior is documented and covered by a regression test.