Use interface, DXC crashed

Description
use interface simply, dxc will crash,but d3dcompile is ok

interface IQueueReadProxy
{
    void GetReadPos(out uint readPos);
};

struct TtQueueReadProxyTest : IQueueReadProxy
{
    void GetReadPos(out uint readPos)
    {
        readPos = 0;
    }
    uint Dequeue1()
    {
        uint readPos = 0;
        GetReadPos(readPos);
        return (uint)readPos;
    }
};

[numthreads(1, 1, 1)]
void CS_ClusterCullingMain(uint DispatchThreadId : SV_DispatchThreadID)
{
    TtQueueReadProxyTest q;
    uint a = q.Dequeue1();
}

Steps to Reproduce

save code in test.hlsl
dxc -E CS_ClusterCullingMain -T cs_6_6 -Fo myshader.bin -Zi -Fd myshader.pdb -D MYDEFINE=1 test.hlsl

Actual Behavior

Internal compiler error: access violation. Attempted to read from address 0x00000000000000A8

Environment

• DXC version dxcompiler.dll: 1.8 - 1.7.0.4386 (a743e97f8)
• Host Operating System <!--- Host operating system and version ---> win10

Reproduce the crash with test.hlsl using the provided dxc command and confirm the access violation on the stated DXC version. Trace the compiler path handling the interface call and out parameter, then add a regression test that compiles the sample without an internal compiler error and verify the existing test suite passes.