message: Don't list a partial callstack for code without debug info
diff: @@ -1924,6 +1924,12 @@ rdcarray<ShaderDebugState> Debugger::ContinueDebug()
  state.callstack.insert(insertPoint, scope->name);
  }
  + // if this instruction has no scope, don't give it a callstack
  + if(GetScope(endOffs) == NULL)
  + {
  + state.callstack.clear();
  + }
  +
  // move to the next inline up on our inline stack. If we reach an actual function
  // call, this parent will be NULL as there was no more inlining - the final scope will
  // refer to the real function which is already on our stack
  