   0  inline_call_ir_r <JitCode 'interp_w__W_IOBase'>, I[$False], R[%r0] -> %r0
   8  -live- %r0
   8  -live- %r0
   8  guard_class %r0 -> %i0
  11  getfield_raw_i %i0, FieldDescr<pypy.module._io.interp_iobase.W_IOBase_vtable.cls__check_closed> -> %i0
  16  -live- %i0, %r0
  16  int_guard_value %i0
  18  residual_call_r_v %i0, <IndirectCallTargets>, R[%r0, $<* struct rpy_string>], <CallDescr(rr) EF=7>
  25  -live- %r0
  25  ref_return %r0
