   0  inline_call_r_r <JitCode 'ObjSpace.bufferstr_w'>, R[%r0] -> %r0
   6  -live- %r0
   9  residual_call_r_r $<* fn b2a_uu>, R[%r0], <CallDescr(r) EF=5> -> %r0
  16  -live- %r0
  19  ref_return %r0
