Do not test nodes with static params as it is too difficult
  	to do from the top-level automatically. Indeed, it would
	require to build effective static arg before, which would
	require to make node_check mutually recursive with type_check
	and co. Its not worth the trouble, as such node can be tested
	anyway if used.

LazyCompiler.solve_node_idref:
	compile (with the new function check_static_arg) static
	params instead of ignoring them.

EvalConst.eval_const -> EvalConst.f
	for simplicity and homogeneity with the naming scheme used in EvalType.