$ ./1.without_utf8.pl 
string is Gödel
SV = PV(0x5584c04dbda0) at 0x5584c0505a88
  REFCNT = 1
  FLAGS = (POK,IsCOW,pPOK)
  PV = 0x5584c052d400 "G\303\266del"\0
  CUR = 6
  LEN = 10
  COW_REFCNT = 1
string is über
SV = PV(0x5584c04dbda0) at 0x5584c0505a88
  REFCNT = 1
  FLAGS = (POK,IsCOW,pPOK)
  PV = 0x5584c0515040 "\303\274ber"\0
  CUR = 5
  LEN = 10
  COW_REFCNT = 1
string is alleß
SV = PV(0x5584c04dbda0) at 0x5584c0505a88
  REFCNT = 1
  FLAGS = (POK,IsCOW,pPOK)
  PV = 0x5584c050d0d0 "alle\303\237"\0
  CUR = 6
  LEN = 10
  COW_REFCNT = 1
$