$x:
SV = IV(0x9575ac0) at 0x955a75c
  REFCNT = 1
  FLAGS = (IOK,pIOK)
  IV = 10
$main::y:
SV = IV(0x9575ac0) at 0x955a75c
  REFCNT = 2
  FLAGS = (IOK,pIOK)
  IV = 10

In block with local $x
$x:
SV = IV(0x9575ac4) at 0x9559c28
  REFCNT = 1
  FLAGS = (IOK,pIOK)
  IV = 20
$main::x (just to note that $x and $main::x are the same thing):
SV = IV(0x9575ac4) at 0x9559c28
  REFCNT = 1
  FLAGS = (IOK,pIOK)
  IV = 20
$main::y:
SV = IV(0x9575ac0) at 0x955a75c
  REFCNT = 3
  FLAGS = (IOK,pIOK)
  IV = 10

After exiting the block with local $x
$x:
SV = IV(0x9575ac0) at 0x955a75c
  REFCNT = 2
  FLAGS = (IOK,pIOK)
  IV = 10
$main::y:
SV = IV(0x9575ac0) at 0x955a75c
  REFCNT = 2
  FLAGS = (IOK,pIOK)
  IV = 10