BUG #13898: ecpg complains on nested comments in /usr/pgsql-9.4/include/informix/esql/datetime.h

The following bug has been logged on the website:

Bug reference:      13898
Logged by:          vladimir zvagolskiy
Email address:      vladimir.zvagolskiy@nasdaq.com
PostgreSQL version: 9.4.5
Operating system:   Centos 7.1
Description:

Hi guys,

We experience a ecpg build issue for INFORMIX dialect:

[vlzv@inetlinux10 ecpg_9.4_issue]$ cat simple.ec
EXEC SQL include datetime;


[vlzv@inetlinux10 ecpg_9.4_issue]$ /usr/pgsql-9.4/bin/ecpg -C INFORMIX -I
/usr/pgsql-9.4/include/informix/esql simple.ec
/usr/pgsql-9.4/include/informix/esql/datetime.h:9: ERROR: nested /* ... */
comments

[vlzv@inetlinux10 ecpg_9.4_issue]$ rpm -qf
/usr/pgsql-9.4/include/informix/esql/datetime.h
postgresql94-devel-9.4.5-1PGDG.rhel7.x86_64


once I modify datetime.h file as per below diff, the issue disappears.
[vlzv@inetlinux10 ecpg_9.4_issue]$ cat -n
/usr/pgsql-9.4/include/informix/esql/datetime.h
     1  /* src/interfaces/ecpg/include/datetime.h */
     2
     3  #ifndef _ECPG_DATETIME_H
     4  #define _ECPG_DATETIME_H
     5
     6  #include <ecpg_informix.h>
     7
     8  #ifndef _ECPGLIB_H                              /* source created by
ecpg which defines thes
     9                                                                   /*
symbols */
    10  typedef timestamp dtime_t;
    11  typedef interval intrvl_t;
    12  #endif   /* ndef _ECPGLIB_H */
    13
    14  #endif   /* ndef _ECPG_DATETIME_H */

[vlzv@inetlinux10 ecpg_9.4_issue]$ diff
/usr/pgsql-9.4/include/informix/esql/datetime.h
/usr/pgsql-9.4/include/informix/esql/datetime.h.orig
9c9
<                                                                /* symbols
*/
---
>                                                                * symbols
*/


[vlzv@inetlinux10 ecpg_9.4_issue]$ /usr/pgsql-9.4/bin/ecpg -C INFORMIX -I
/usr/pgsql-9.4/include/informix/esql simple.ec
[vlzv@inetlinux10 ecpg_9.4_issue]$ ls -l ./simple.c
-rw-rw-r-- 1 vlzv vlzv 700 Jan 29 11:15 ./simple.c