Z80 Routines:Optimized:CpHLDE

This is a faster/smaller replacement for the typical CpHLDE routine.

Typical routine:

CpHLDE:
  push hl
  or a
  sbc hl,de
  pop hl
  ret

Better routine:

CpHLDE:
  or a
  sbc hl,de
  add hl,de
  ret