Do not crash when checking semantics of undeclared symbolic_variable.
NOTE: this update may have broken the printing of error messages
during semantic analysis of IL code.

.project

syntax: regexp
\.o$
syntax: regexp
^iec2c$
syntax: regexp
^iec2iec$
syntax: regexp
\.depend$
syntax: regexp
^stage1_2/iec\.(y|flex)\..*$