$ 5.42t/bin/perl -MDevel::Peek -e'Dump( "z" x 6 )'
SV = PV(0x607fa35c4200) at 0x607fa35f2138
  REFCNT = 1
  FLAGS = (PADTMP,POK,IsCOW,READONLY,PROTECT,pPOK)
  PV = 0x607fa3603d10 "zzzzzz"\0
  CUR = 6
  LEN = 16
  COW_REFCNT = 0

$ 5.40t/bin/perl -MDevel::Peek -e'Dump( "z" x 6 )'
SV = PV(0x5d8bda39d200) at 0x5d8bda3cafb8
  REFCNT = 1
  FLAGS = (PADTMP,POK,READONLY,PROTECT,pPOK)
  PV = 0x5d8bda3d5340 "zzzzzz"\0
  CUR = 6
  LEN = 16