+- designator support for initializers
+- add constant folding code
+- Refactor code, so code to handle number values and strings is
+ an own module and replacable
+- Support some attributes. noreturn, unused, printf, scanf, packed would be
+ interesting candidates
+- SourcePositions could be stored selectively on expressions that really need
+ them.
+- check semantic for functions declared/defined in global scope and declared
+ again in a local scope