   0  inline_call_r_r <JitCode 'allocate_instance__W_Chain'>, R[%r0] -> %r0
   6  -live- %r0, %r1
   6  inline_call_r_r <JitCode 'iter'>, R[%r1] -> %r1
  12  -live- %r0, %r1
  12  setfield_gc_r %r0, %r1, FieldDescr<pypy.module.itertools.interp_itertools.W_Chain.inst_w_iterables>
  17  setfield_gc_r %r0, $<* struct pypy.interpreter.baseobjspace.W_Root>, FieldDescr<pypy.module.itertools.interp_itertools.W_Chain.inst_w_it>
  22  -live- %r0
  22  goto_if_not_ptr_iszero %r0, L1
  26  ref_return $<* struct pypy.interpreter.baseobjspace.W_Root>
  28  ---
  28  L1:
  28  ref_return %r0
