Handle initialising a DXIL constant struct to NULL

It is a nop because ShaderVariable starts initialised to 0

renderdoc/driver/shaders/dxil/dxil_debug.cpp

@@ -1057,6 +1057,11 @@ static bool ConvertDXILConstantToShaderVariable(const Constant *constant, Shader
     }
     return true;
   }
+  else if(constant->isNULL())
+  {
+    // Nothing to do because Shader Variables created initialised to zero
+    return true;
+  }
   return false;
 }
 

util/test/demos/d3d12/d3d12_workgroup_zoo.cpp

@@ -104,7 +104,7 @@ void main(uint3 inTid : SV_DispatchThreadID)
   tid = inTid;
   float4 data = 0.0f.xxxx;
   uint id = WaveGetLaneIndex();
-  gsmUint4[id] = id;
+  gsmUint4[id] = id.xxxx;
   SetOutput(data);
 
   if(IsTest(0))