In the -2c mode, in presence of extern types, I was defining them as int.
The idea was to have something that compiles, and then to ask the user
to redefine its extern types.

Now I define extern types as string (char*).

The rationale of this change is that before, the generated code was only
working for int, which is pretty useless as an extern type.

Have string by default is actually much more useful, for instance to use
string in a Lustre program.

Also, adapt to changes done in lutils, where the string type has ben added.
(sha:8619aa285ca8322ab9, i.e., > lutils  1.49.10)

Remove a lot of warnings (considered as errors by dune).

The generated code for tests on boolean output was wrong. Indeed, it
was generating

  if (o1 == _true) {

instead of

  if (*o1 == _true) {

nb : a warning was emited

I've fixed that using memcmp, which should be fine since compared elements
are of the same types.

+ add a test that reveal a pb in the generated C code in lustre programs
that perform equalities on arrays.

Reference Manual enhancements.

by grouping instances of the same type into arrays.

The rationale is to be able to generate for loops with iterators.

The previous code was working, but probably by chance.

Indeed, in order to copy an array, I used to generate something like

   memcpy(out, in, sizeof(in));

but if 'out' and 'in' are arrays, and if 'in' is an argument of a function,
sizeof() considers it as a pointer, not an array !!!!

note that if 'in' is a local var, sizeof(in) works fine.

To fix it, I use the type of the dest (instead of the id) as argument of sizeof.

nb : The pb never occured before, as in the heap mode only the ctx is
passed a args of step functions.

There were problems with arrays

There were problems with:
- arrays in step functions (array were declared with an incorrect syntax)
- the node_loop.c file was wrong in presence of arrays in I/O
- clock that are outputs (a "*" was missing)

when calling soc.

Do not work all the times (eg, with arrays it generates C code that
does not compile). cf next changes.

i.e., by providing a default macro definition that uses memcpy()
(versus generating a nop function).

As suggested by Willie, it allows it to be specialized when it is
called more than once.

The rationale is to prepare the work for a future --2s-stack option.

Also provide a default version of those macros using memcpy.

Add an option --to-c-dont-inline-predef to get the previous behavior.

I've just switched to ocaml 4.02, and it works only on carlit because
of GLIC 2.14 is not installed on other machine.

also, add some missing files.

Indeed, ite are polymorphic, and thus inventing names during soc
instanciation is error-prone, ugly, innefficient, and increase the
code size.

Moreover, using C ite to translate them online (ie, without going
trough a soc) is straigforward

# of unexpected failures	104->101.

where I've removed the handling of polymorphism.

For instance,
  node toto = map<<Lustre::if,  N>>(x, a, b);
is rejected.

The problem with this change is that we now also reject equations such as
   res = map<<+,  N>>(x, a, b);

which could be avoided. Probably L2lRmPoly does its job partially.

nb:  unexpected failures  115->120

nb:  unexpected failures 120 -> 115

I've sligthly modified the profile of gen_assign to explicitly ask for the
size of the data structure to be copied.

nb:  unexpected failures 131 -> 127

nb:  unexpected failures	144->143

The first one in Soc2cIdent.type_to_short_string when enum and int were both
translated by "i" ; as a consequence, some different soc ctx get the same name.

The second one was due to the fact that car ident in gao switches were
printed incorrectly (missing "ctx->" or "node_no_mem_ctx.").

nb:  unexpected failures 162-> 149

nb:  unexpected failures 175-> 162

Also name step function consistent and uniquely

Always use Soc2cPredef.gen_assign to generate var assignments.

Also, use affection for assigning structures.

nb: 21 more tests passes.