Internal error 200307043 + REGVAR + Windows

FPC [main] x64+x32 Windows

---

program app;

var
  p1, p2, p3: Pointer;

begin
  p1 := p2 - (nil - p3);
end.

fpc.exe -n -FuC:\fpclaztrunk\fpc\units\x86_64-win64\rtl -OoREGVAR app.pas

Related: #13815 (closed)