Fix bug: Add support for de-referencing pointers to struct (struct_ptr^.elem1) when used inside FB.
Note that multiple de-referencing of structs (struct_ptr_ptr^^.elem) is not supported inside FB code (this would need BIG changes to the compiler!)

iec.flex.c
iec.y.output
iec.y.cc
iec.y.hh
Makefile.depend