Bug 13 (expt 0 0) -> 0, release-critical or not?

[Rob Browning]

The bug:

  bug 13 -- (expt 0 0) -> 0
  reported-by: rlb / 2001-03-21
  fixed: not-yet

  According to R5RS (expt 0 0) -> 1

Also filed as bug 15 in HEAD.

I already have a fix for this, but as-per my earlier suggestions I'd
like to start discussing non-trivial freeze changes before making
them.

In frozen I'd just change boot-9.scm to check for the zero? case.
That way we're guaranteed not to affect any other intenal code that
might depends on the particular quirks of integer-expt in numbers.c

For unstable, I'd go ahead and fix integer-expt directly, but not
immediately.  I've been working on the issues involved in using gmp
with guile, and I'd probably just handle it during that process.

Thoughts?

-- 
Rob Browning
rlb @defaultvalue.org, @linuxdevel.com, and @debian.org
Previously @cs.utexas.edu
GPG=1C58 8B2C FB5E 3F64 EA5C  64AE 78FE E5FE F0CB A0AD