It doesn't even need to be a modern language to protect against that:

  BEGIN
    INT x := 1;
    print(("x is", x, newline));

    GOTO later;

    INT y := 2;

   later:

    print(("y is", y, newline))
  END

for which we have:

  $ a68g goto.a68 
  x is         +1
  11           print(("y is", y, newline))
                            1           
  a68g: runtime error: 1: attempt to use an uninitialised REF INT value (detected in [] "SIMPLOUT" collateral-clause starting at "(" in this line).

Although admittedly it is a runtime error.

However if y is changed to 'INT y = x + 2;', essentially a "constant", then there is no runtime error:

  $ a68g goto.a68 
  x is         +1
  y is         +0