[COMMITTED] Don't build readline's shared libs by default

  Since the sync to version 7.0-alpho, readline now by default builds
(unused) shared libraries alongside static libraries, whereas before it
only built static libraries.  A couple of GDB buildbots were not happy
with this change:

  http://gdb-build.sergiodj.net/builders/AIX-POWER7-plain/builds/240
  http://gdb-build.sergiodj.net/builders/Fedora-i686/builds/1518

To get these buildbots building again, this patch alters readline's
configure.ac file to not build shared libraries by default, as was the
case with readline 6.2.  A more permanent fix may be to alter the
top-level Makefile.def to pass --disable-shared to readline, or to
investigate why these building these shared libraries are giving the
buildbots trouble.  (I think the proximate reason why the i686 buildbot
fails is because it passes CFLAGS=-m32 instead of CC="gcc -m32" to the
top-level configure script, and readline's linker commands don't inherit
CFLAGS.  Not sure about the AIX failure.)

readline/ChangeLog.gdb:

	* configure.ac: Default opt_shared_libs to no.
	* configure: Regenerate.
---
 readline/ChangeLog.gdb | 5 +++++
 readline/configure     | 2 +-
 readline/configure.ac  | 2 +-
 3 files changed, 7 insertions(+), 2 deletions(-)
  

On Sat, Jul 25, 2015 at 11:38 AM, Patrick Palka <patrick@parcs.ath.cx> wrote:
> Since the sync to version 7.0-alpho, readline now by default builds
> (unused) shared libraries alongside static libraries, whereas before it
> only built static libraries.  A couple of GDB buildbots were not happy
> with this change:
>
>   http://gdb-build.sergiodj.net/builders/AIX-POWER7-plain/builds/240
>   http://gdb-build.sergiodj.net/builders/Fedora-i686/builds/1518
>
> To get these buildbots building again, this patch alters readline's
> configure.ac file to not build shared libraries by default, as was the
> case with readline 6.2.  A more permanent fix may be to alter the
> top-level Makefile.def to pass --disable-shared to readline, or to
> investigate why these building these shared libraries are giving the
> buildbots trouble.  (I think the proximate reason why the i686 buildbot
> fails is because it passes CFLAGS=-m32 instead of CC="gcc -m32" to the
> top-level configure script, and readline's linker commands don't inherit
> CFLAGS.  Not sure about the AIX failure.)
>
> readline/ChangeLog.gdb:
>
>         * configure.ac: Default opt_shared_libs to no.
>         * configure: Regenerate.

Reverted, along with the original import commit.  This commit message
is mostly bogus; during the import I failed to notice that
configure.in had a number of local changes of its own, including this
one to disable building shared libraries.  It was not a new change
needed specifically for readline 7.0.