[m-rev.] Upgrade Boehm GC to 7.6.0

[Julien Fischer]

Hi Paul,

On Wed, 21 Sep 2016, Paul Bone wrote:

> On Wed, Sep 21, 2016 at 09:29:14AM +1000, Julien Fischer wrote:
>>
>> Hi,
>>
>> On Tue, 20 Sep 2016, Zoltan Somogyi wrote:
>>
>>> On Tue, 20 Sep 2016 18:02:16 +1000 (AEST), Julien Fischer <jfischer at opturion.com> wrote:
>>>>> I've tested this with hlc.gc, hlc.par.gc, asm_fast.gc, asm_fast.par.gc.stseg
>>>>> on x86_64 Linux.  If anyone would like to test on other platforms that'd be
>>>>> good, but it's also okay to test this once its on master.
>>>>
>>>> Go and ahead and commit it to master.  I'll take a look at it on OS X
>>>> and Windows after you do that.
>>>
>>> I am afraid this broke my setup. I use Ubuntu 13.10, and it does
>>> NOT have libtool installed, which is why I get errors such as these
>>> (extracted from the output of make):
>>
>> Paul, I thought you had removed the dependency on libtool; has it crept
>> back in somewhere?
>
> The best I could do last time was to commit the files that libtool
> generates, so that it's not needed during normal builds.  I'm currently
> setting up an environment similar to Zoltan's without libtool so that I can
> see more of what is happening.  Maybe my change didn't go through when
> Zoltan did his testing or maybe I screwed up, not sure.

I just "fixed" the problem another way, by taking ltmain.sh and the
contents of the m4 directory from the libatomic_ops-7.4.4 tarball (from
the Boehm GC webapage) and copying them into my source tree.  It then
works.  (In the git version ltmain.sh is currently a symlink to
somewhere that doesn't exist on my system.)  I think it might be best if
we just commit the above files in the Mercury version of libatomic_ops.

Julien.