digit-argument and inserting numbers

[Chong Yidong]

In bug#771, Jay Belanger pointed out a problem with digit-argument:

> "M-5 0 x" would print 0 five times, followed by an x. However, "M-5 0
> x" will print x fifty times.

The problem is that there isn't an easy way to print `0' five times,
using either digit-argument or C-u.  This may have been discussed
before; if so, can someone point to the discussion and/or summarize the
conclusions?