revert commits improved performance of some extensible Standard Functions (ADD, MUL, AND, OR, XOR)

Following commits are reverted:
mjsousa 0b275a2 improve performance of some extensible Standard Functions (ADD, MUL, AND, OR, XOR) -- increase hardcoded limit to 499
mjsousa 2228799 improve performance of some extensible Standard Functions (ADD, MUL, AND, OR, XOR) -- Add comments!!
mjsousa ce81fa6 improve performance of some extensible Standard Functions (ADD, MUL, AND, OR, XOR)"

The reason is that they cause regression in some cases (if function is
used as argument for function block, for example) and this is not
fixed for a long time.

TYPE
 enum_type00 : (enum_v1, XXXX, enum_v2) := XXXX;
END_TYPE

TYPE
 enum_type01 : (XXXX, enum_v2) := XXXX;
END_TYPE

TYPE
 enum_type02 : (enum_v1, XXXX) := XXXX;
END_TYPE

TYPE
 enum_type03 : (XXXX) := XXXX;
END_TYPE




function foo : int
 var_input
  a_1, b_1: int;
 end_var
 var
  c_1, d_1: enum_type00;
(*
  enum_v1 : enum_type00;
*)
 end_var
  c_1 := enum_type00#XXXX;
  c_1 := XXXX;
  c_1 := enum_v1;
(*
  enum_v1 := enum_v1;
*)
end_function