to avoid priority errors.

iterators (e.g.,  "Lustre::plus" instead of "Lustre::+")  in order to
make the life of lic3loc easier.

to avoid priority errors.

and PredefEvalClock.

SolveIdent.recognize_predef_op  that  replaces  node call  by  Predef
constructor  when   necessary,  via  a  complete   traversal  of  the
SyntaxTree (instead  of doing it  in the parser). The  rationales for
this change are that:

- it is quite tedious to do it in parser as multiple locations are involved
- I did missed some locations
- It makes the parser more focused on parsing issues
- that traversal  is a first step  do deal with  idref solving (hence
 the name of the new module that contains that function

Note that lsrc/test/should_work/fab_test/lecteur.lus was using
"plus" as a variable ident, which raised an error, which

performed. The resulting code is both more compact, and more general.

It is more  general, since that predef operators  are now represented
by  node_exp_eff, exactly as  user nodes.   Hence, all  the functions
that were  operating on  user nodes via  node_exp_eff (such  as, node
aliasing) works for free on predef op!

In order to be able  to perform that generalisation, it was necessary
to  extend sligthly  the data  structure used  to represent  the node
profile in CompiledData.node_exp_eff with information indicating if a
variable is polymorphic or overloaded.

Not that, currently, polymorphic  or overloaded variables can only be
introduced by predef  operators. But I think it would  be easy to add
those notions for normal user nodes after this change.

New non-reg files boolred now compiles. Those involving
- boolred
- alias on predef.op

(support for fill, red, etc. is coming soon).

In order to add support  for iterators, I have extended the by_pos_op
(and the by_pos_op_eff) data type with a list of static arguments. In
other words, iterators are handled as a particular case of predefined
operators.

tests.

Also, Add the possibility to have several lustre files in the
command-line arguments.

remove the power operator.

Define a lustre.lus that contains a packaged version of Lustre
predefined operators. It will be in the standard lustre library,
and should be accessible directly (path).

For non-regression tests, do not use Lazycompiler.test function
anymore and just use  LazyCompiler.node_check instead.

put in the new file compiledDataDump.ml all the stuff
related to string convertions of CompiledData items.

and anonymous structures. I've even found some type errors in the non-reg files!

operators. Predef contains the abstract syntax of those operators (taken
for SyntaxTreeCore.by_pos_op), and PredefSemantics contains:

 - const_eval: that says how to statically evaluate constants
 - type_eval: that provides the type profile of predef operators
 - clock_eval: that provides the clock profile of predef operators

The code in EvalConst that dealt with predef const evaluation is now in
Predef.const_eval