Rewriter: entrypoint function's param referenced types are removed when param is not used.

Hello,
the following shader rewrite with dxr.exe -remove-unused-functions -remove-unused-globals -E ps_main

struct VS_OUTPUT
{
    float4 position : SV_Position;
    float4 uv : TEXCOORD0;
    float4 color : VC;
};   

float4 ps_main(VS_OUTPUT input) : SV_Target0 
{
    return float4(0, 0, 0, 0);
}

output will be

float4 ps_main(VS_OUTPUT input) : SV_Target0 
{
    return float4(0, 0, 0, 0);
}

Start by running the HLSL reproducer with dxr.exe using -remove-unused-functions, -remove-unused-globals, and -E ps_main, then trace the rewriter's handling of the ps_main entrypoint parameter and its referenced VS_OUTPUT type. Done means the rewritten output preserves the required parameter type definition even when the parameter is not used.