Attempting to pass a texture in the AS->MS payload struct causes crash

Description
Attempts to compile the following code results in an internal crash in the compiler.
(GetLoweredUDT() returns nullptr when passed the payload's type)
(This happened while writing tests. Not a customer scenario AFAIK)

Steps to Reproduce

// -T as_6_6 
struct MyPayload
{
    Texture2D tex;
};

[numthreads(1, 1, 1)]
void main(uint gid : SV_GroupID)
{
  MyPayload payload;
  DispatchMesh(1, 1, 1, payload);
}

Actual Behavior
Asserts, then crash

Environment

• DXC version: dxcompiler.dll: 1.8 - 1.8.0.4583 (compiled from github top-of-tree, circa 5/10/2024)
• Host Operating System Win11, insider flight

Start by compiling the provided AS->MS payload reproducer with DXC and inspect the compiler path where GetLoweredUDT() receives the payload type. The issue names no source files or tests, so locate the relevant lowering code and establish regression coverage for this case. Done means the reproducer no longer asserts or crashes.