bin/build-utils.sh::
 * asdf is not part of build-utils.sh

 bin/build.sh::
 * Build asdf as part of the normal build because it's always part of
   the main tarball, not the extras tarball.

bootfiles/20d/boot-2012-12-1.lisp::
  Add :alien-callback to *features*

bin/build.sh::
  Change bootstrap directory to 20d.

code/lispinit.lisp::
  * Register :alien-callback feature if enabled.
  * Heap overflow checking depends on gencgc, so register that only if
    both are enabled.

tools/comcom.lisp::
  Compile c-callback only if :alien-callback is a feature.

tools/worldcom.lisp:
  Compile alien-callback onlf if :alien-callback is a feature.

Useful, for example, for doing a full build with reduced space sizes
or stack sizes.

bootfiles for 20a.

o Add -U option.  This causes the updated translations to overwrite
  the *.po files in source tree.  Without -U, the diff of the changes
  are printed, as before.  The -U option is useful to prepare the po
  files for checking in to the CVS repository.

lisp/GNUmakefile:
o Put back the original translations target and rule, but rename the
  target to tranlations-update.  This allows developers to overwrite
  the translations in the source tree, ready for analysis or checkin,
  as appropriate.

openSuSE 11.2 system, gcc messages are garbled unless I do this.
(Perhaps, I'm missing some localization info?  But I have the gcc
localization package installed.)

new pot files and don't update the translations (po and mo files).

the default build-world.sh.  (Requested by Alex G.)

too.  (It's already applied to the other builds.)

lisp/GNUmakefile:
o Change "all" target to build just lisp.nm.  Don't also build the
  translations target.

tools/build.sh:
o Only make translations for the last build.

boot-2010-02-1 as the bootstrap file.  You should probably also use
the new -P option for build.sh to generate and update the po files
while building.

o Add RCS header

make-dist.sh:
o Add RCS header
o Add some comments on what this does.

last build because we need the libraries to persist so we can have x87
and sse2 versions of them.

unicode-utf16-extfmt-2009-06-11.

Requested by Stelian Ionescu to support Gentoo.  Some Gentoo systems
don't have /usr/bin/time.  (What kind of Unix system doesn't have
/usr/bin/time?)

don't have to if the C code truly didn't change, but this script can't
tell that so always run build world twice.

sse2-packed-2008-11-12).

build.  The subsequent builds shouldn't have changed any C code.

a core file with the right addresses for undefined_tramp and
closure_tramp.

Only needed on Solaris and ppc.

program, but does set the exit code appropriately.