检测嵌套注释
理由应避免嵌套注释，因为它们难以读取。
重要性：低
PLCopen 规则：C3
示例
{attribute 'do-analysis'}
(* That is
(* nested comment 1 *)
*)
PROGRAM PLC_PRG
VAR
(* That is
// nested comment 2
comment *)
iVal1: INT;
iVal2: INT;
(* That is
(* nested comment 3 *) *)
pVal3: POINTER TO DWORD;
hugo: INT;
END_VAR
(* That is
// nested comment 4
comment *)
iVal1 := iVal1 + 1;
(* That is
(* nested comment 5 *)
*)
(* Not that one *)
--> SA0163: Nested comment 'nested comment 1'
--> SA0163: Nested comment 'nested comment 2'
--> SA0163: Nested comment 'nested comment 3'
--> SA0163: Nested comment 'nested comment 4'
--> SA0163: Nested comment 'nested comment 5'