[Bug-ed] POSIX incompatibility - List command should escape $

[Ori Avtalion]

The standard says this about the list command:
  "The end of each line shall be marked with a '$', and '$' characters
within the text shall be written with a preceding <backslash>"

GNU ed 1.14.2 doesn't conform (as well as FreeBSD):

$ ed
a
It cost $5
.
l
It cost $5$

Should have printed:
It cost \$5$

This has been fixed yesterday in OpenBSD:
https://marc.info/?l=openbsd-cvs&m=152474514713081&w=2