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

Add code to support empty arrays (not yet working)

And it is now done only by Lic2soc (L2lCheckLoops is not used anymore)

Also, during this change, I was bitten again by the « "__" versus "::" in ident
names » problem again.

The core of this problem is due to the fact that I use LicDump both for
(1) dealing with internal ident names
(2) generating lustre files

Because of (2), ident names may depend on the ec or the v4 option. hence, internal
names were sometimes translated with "__" instead of "::".

To (try to) fix that, I've added a boolean flag to all "to_string" functions that
states whether the function is used for internal purposes, or for generating lustre
files.

It was quite a boring change, that triggered other problems, that I've fixed
in this (too long) commit :
 - -esa should force -en, otherwise bad things happen (-esa is used for -ec anyway)
 - in -esa mode, #/nor inputs tuples of bool, not arrays
 - fix the list of predi op that returns a type different that its arg (SocPredef)

nb : i have changed the var name in the generated nodes, which was a bad idea
(=painful to get it rigth again).

Ditto for Misc and Compile

nb : the -exec mode was working because I did not use the generated soc,
which was completely wrong.

Note that to do that, I have modified the CURRENT variant of
Lic.val_exp, to attach it the clock the current holds on. Indeed, the
clock is mandatory to generated correct code...

In an ideal world, this clock information may have explicitely been
set by the user ("current(clk_of_X,X)" instead of "current(X)"), but
for historical reason, it is not the case.

Hence, this information is added as soon as it is available, namely,
during clock checking.

As far as ldbg is concerned, it only traces the toplevel node, at
call event.

Note that I needed to rename quite a lot of modules to avoid name clashes
between lus2lic.a and ltop.

I've also merged the Verbose module with the one of Lutin so that
they can be shared (there were sharing 95% already).

In order to do that, I've generalised the type of merge : now the clock
argument can be any expression. Some assert false still prevent its use,
but it should be easy to get rid of them (I'll do that latter).

nb : programs do run, but I did not check that they run correctly...

Also fix a regression introduced in the previous change where
incorrect ec code was generated for diese.

1) At the Lic level, there's no reason to distinguish betwenn node
calls, and predef node calls. Indeed it makes things simpler and more
homogeneous afterwards.

2) int strings are only converted when necessary (constant evaluation).

3) const are handled directly under Lic.by_pos_op instead of being under
   PREDEF_CALL, which make things easier and more logical.

BTW, put everything that concerns node environement into the new
IdSolver module (from the Lic module).

Pascal prepared « the field » for that change.

Also, force the merge to operate over an ident rather than on any val_exp.

nb : do not work for lv4/ec mode

Also fix some bugs in DumpLic when printing condact in other modes.

Remove all test that now passes from the broken dir.

nb: les tests ne passent toujours bien sur.

* Partie lus -> AST

predef.ml -> srcPredef.ml
syntaxTreeCore.ml -> astCore.ml
syntaxTree.ml     -> astV6.ml
syntaxTreeDump.mli-> astV6Dump.mli

* Partie Ast -> Ast

solveIdent.mli -> astRecognizePredef.mli
syntaxTab.mli -> astTab.mli
symbolTab.mli -> astTabSymbol.mli

* Partie  AST -> lic (static evaluation)

eff.ml  -> lic.ml
getEff.mli -> ast2lic.mli
lazyCompiler.mli -> licTab.mli
builtIn.ml -> licMetaOp.ml
predefEval*.ml -> licEval*.ml
name.mli -> licName.mli

* Partie Lic -> Lic

uniqueOutput.mli      -> l2lCheckOutputs.mli
structArrayExpand.mli -> l2lExpandArrays.mli
nodesExpand.mli       -> l2lExpandNodes.mli
doNoPoly.ml           -> l2lRmPoly.ml
doAliasTypes.ml       -> l2lAliasType.ml
doSplit.ml            -> l2lSplit.ml

et donc ne marchent plus !

IDENT remplacé par VAR_REF/CONST_REF
- plus de node_exp dans les CALL, juste une ref (node_key)
- reste a faire pareil pour les NodeStaticArgEff

importante du mecanisme de UnifyType :
- fait :
  * definition de Eff.poly_match
  * TypeVar type_var au lieu de Any/Overload
    avec type_var = Any | AnyNum
    (pour l'instant et pour longtemps ?!)
- à faire :
  * revoir UnifyType pour qu'il rende un poly_match
  * stocker là où c'est nécessaire les poly_match
    calculés lors du type check
    (pour les CALL et peut-être les sargs ?)

Fix a performance bug that was occuring with programs having a lot of variables and that were using constant.

maintaining (ugly and error-prone) hash tables.

That change revealed an untriggered bug in EvalClock.check_args: it was wrong
to add in subst the substitutions made of the parameters and the arguments (it
is enough to unify the clocks of the pars and of the args). For instance, consider
the node (in should_work/clock/clock.lus)

   node clock5(x :  bool; y:  bool when x; z: bool when y)

and the call

  z2 = clock5(a, b when a, c when e);

I was adding y/b in the subst, which was wrong.

Other minor changes:
 - move const_to_val_eff from Eff to UnifyClock.
 - GetEff.translate_val_exp now returns a substitution, in order to be able
   to unify clock vars and propagate the resulting substitution.

info is attached to all  val_exp. Moreover, this allow to perfrom all
the  type checking  in  EvalType.f, instead  of  doin part  of it  in
GetEff.translate_val_exp.

maintaining (ugly and error-prone) hash tables.

as extern constants.

Also  fix  a  bug   in  the  struct/array  expanser:  when  expanding
structured constants  into val_exp,  I need to  add a entry  into the
type and clock val_exp tables.

2 source transformations), we add an entry in the EvalType and the EvalClock
tables. Otherwise, when we use EvalType.lookup or EvalClock.lookup, an error
migth be raised.