[m-rev.] for post-commit review: fix a perf bug

[Julien Fischer]

Hi Zoltan,

On Wed, 2 Dec 2015, Zoltan Somogyi wrote:

> On Tue, 24 Nov 2015 16:28:07 +1100, Julien Fischer <jfischer at opturion.com> wrote:
>>> OK. If you haven't started deleting them yet, I will.
>>>
>>
>> No, I haven't touched them.
>
> OK. Here is the diff deleting auto-init for solver vars.
> For review by Julien.

...

> Remove the code for automatic initialization of solver vars.
> 
> We haven't supported it in years, and keeping it in the compiler
> is just a maintenance burden and a performance problem.

...

That's fine.  There are some other spots that also deal with init predicates,
for example:

    deep_profiler/read_profile.m:743
    runtime/mercury_layout_util.c:1030
    runtime/mercury_stack_trace.c:2096

I don't know if you want remove those now or leave them.

Julien.