Allow array_dimension_iterator to accept an array_spec_init_c.
Fixes bug activated by generating C code from IL code containing array variables.

STD_TEST.st
STD_RESSOURCE.c
LOCATED_VARIABLES.h
POUS.c
test
STD_CONF.c
SFC_TEST.st
test.exe
plc.st
POUS.h
VARIABLES.csv