Fix datatype analysis of conditional IL operators (CALC, CALCN, RETC, RETCN, JMPC, JMPCN, S and R)

Fix datatype analyses of S and R IL operators.

make sure all IL operands are narrowed (datatype checking algorithm)

cosmetic change only - fix code alignment.

Add support for FB call semantics of 'S' and 'R' IL operators!
Remove segfaults when analysing buggy IL code (IL operators with no operands).

Stop lvalue check from segfaulting when coming across buggy IL code (IL operator with no operand!)

Allow get_datatype_info_c to be called with NULL parameters.

Do lvalue check of function output parameters (since they may contain expressions inside array subscripts!)

Handle buggy source code gracefully (do not bork when non-array variable is used as an array. e.g: int_var[42]:= 33)

Delete debugging messages left in by mistake.

Fix segfault when doing lvalue check of buggy IEC 61131-3 source code

Fix datatype analysis of structured variables that contain arrays in their fields (e.g. var.x1[var2 + 42].y1).

Add capability of returning array subscript list while decomposing a struct/array variable.

Code cleanup: Remove unused option = Delete dead code.

merge

Declare that YYLSTYPE is not the default trivial datatype used by bison. (was causing compile errors in bison ver >= 2.7)