When a local label was seen, the debug backend would not receive the
full label name! In order to both simplify the code and avoid this
kind of discrepancy again, make both the output and debug format calls
from a common static function.
However, none of the current debug format backends want to see NASM
special symbols (that start with .. but not ..@) so filter those from
the debug backend.
Finally, fix an incorrect comment in nasm.h: the debug format is
called *after* the output format.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Jim Kukunas <james.t.kukunas@linux.intel.com>
