why no $pc offset in debug CFA?

[DJ Delorie]

In dwarf2out.c : dwarf2out_frame_init we have this code:

#ifdef DWARF2_UNWIND_INFO
  if (DWARF2_UNWIND_INFO)
    initial_return_save (INCOMING_RETURN_ADDR_RTX);
#endif

However, gdb really needs that slot to unwind stack frames when
debugging, on targets that don't use dwarf2 unwinding (i.e. cygwin
with -gdwarf-2, and some embedded targets that still use sjlj).  Why
don't we unconditionally emit this?