Don't ever flush immediate values in shader debugging

* We assume that fxc won't output a denormalised float in the bytecode, and this
  prevents us from flushing integer inputs to otherwise flushable float-type
  operations

renderdoc/driver/shaders/dxbc/dxbc_debug.cpp

@@ -1532,6 +1532,8 @@ ShaderVariable State::GetSrc(const Operand &oper, const Operation &op, bool allo
     {
       s.name = "Immediate";
 
+      flushable = false;
+
       if(oper.numComponents == NUMCOMPS_1)
       {
         s.rows = 1;