issue #8817 If \if, \else or \endif is in a list, the subsequent list…

… entry is not formatted as list entry but in "raw format"

Looking at the results of the version 1.9.1 the result is OK, in the 1.9.2 version it is not OK.
Having:
```
/**

\mainpage

-# '1'
-# '2'
\if ASDF
-# '3' IF-CASE ASDF \line8
\else
-# '3' ELSE-CASE ASDF \line10
\endif
-# '4'

*/
```
we see with `doxygen -d commentscan` in the 1.9.2 version:
```
CommentScanner: D:/speeltuin/issue_8817/DoxyIfElse/Input.dox:3
output=[
brief=[line=-1
]
docs=[line=5
-# '1'
-# '2'
\iline 8 -# '3' IF-CASE ASDF \line8
\iline 12 -# '4']
inbody=[line=-1
]
]
```
i.e. the `-#` is not at the beginning of the line anymore  due to the `\iline` (which was necessary to have correct line numbers for warnings).
We need an extra newline, not a normal newline, as this would disturb the line counting process,  but a doxygen internal newline i.e. `\ilinebr `

src/commentscan.l

@@ -3309,7 +3309,7 @@ static inline void addOutput(yyscan_t yyscanner,char c)
 static void addIline(yyscan_t yyscanner,int lineNr)
 {
   char cmd[20];
-  sprintf(cmd,"\\iline %d ",lineNr);
+  sprintf(cmd,"\\iline %d \\ilinebr ",lineNr);
   addOutput(yyscanner, cmd);
 }