3.1.6 release candidate test results -- and one patch

[Robert Goldman]

On Linux, I checked:

ccl sbcl cmucl allegro allegromodern allegro8 allegromodern8 lispworks
clisp ecl ecl_bytecodes mkcl

All passed, except ECL and ECL with bytecodes, both of which failed
test-xach-update-bug.script

But I have only ECL 13.5.1, so this may be wrong.

Also note that I checked only with ACL 9.  I don't have the ACL 10
release candidate on this machine.  But I assume Kevin will have tested
that case.

On Mac, I checked:

ccl clisp sbcl cmucl lispworks allegro_64 allegromodern_64 allegro8_64
allegromodern8_64 allegro_64_s allegromodern_64_s allegro8_64_s
allegromodern8_64_s abcl

All tests on these lisps pass.

On SBCL on the Mac, with version 1.2.15.0.sbcl-1.2.15.0-4bc676e, the
tests failed before running, because the ASDF build failed with a
deprecation warning.

That was because we use SB-DEBUG:BACKTRACE (deprecated) instead of
SB-DEBUG:PRINT-BACKTRACE.  I made that change and pushed.  I'm hoping we
don't need to protect this patch with checks to avoid earlier versions
of SBCL.

For Allegro on the Mac, I checked with both Allegro 9.0 and the Allegro
10.0 pre-release.

I'll try Windows next, and if that works, release 3.1.6.

Cheers,
r