Sorry, accidently committed a patch I'm working on. Reverting it.

The only correct change was:
- Added SQLSTATE macro closing bug #3961.

src/interfaces/ecpg/include/datetime.h

-/* $PostgreSQL: pgsql/src/interfaces/ecpg/include/datetime.h,v 1.13 2008/02/14 12:22:36 meskes Exp $ */
+/* $PostgreSQL: pgsql/src/interfaces/ecpg/include/datetime.h,v 1.14 2008/02/14 12:27:26 meskes Exp $ */
 
 #ifndef _ECPG_DATETIME_H
 #define _ECPG_DATETIME_H
 
 #include <ecpg_informix.h>
 
-/* typedef timestamp dtime_t;
-typedef interval intrvl_t;*/
+typedef timestamp dtime_t;
+typedef interval intrvl_t;
 
 #endif   /* ndef _ECPG_DATETIME_H */

src/interfaces/ecpg/include/decimal.h

-/* $PostgreSQL: pgsql/src/interfaces/ecpg/include/decimal.h,v 1.15 2008/02/14 12:22:36 meskes Exp $ */
+/* $PostgreSQL: pgsql/src/interfaces/ecpg/include/decimal.h,v 1.16 2008/02/14 12:27:26 meskes Exp $ */
 
 #ifndef _ECPG_DECIMAL_H
 #define _ECPG_DECIMAL_H
 
 #include <ecpg_informix.h>
 
-/* typedef decimal dec_t; */
+typedef decimal dec_t;
 
 #endif   /* ndef _ECPG_DECIMAL_H */

src/interfaces/ecpg/include/ecpg_informix.h

 /*
  * This file contains stuff needed to be as compatible to Informix as possible.
- * $PostgreSQL: pgsql/src/interfaces/ecpg/include/ecpg_informix.h,v 1.19 2008/02/14 12:22:36 meskes Exp $
+ * $PostgreSQL: pgsql/src/interfaces/ecpg/include/ecpg_informix.h,v 1.20 2008/02/14 12:27:26 meskes Exp $
  */
 #ifndef _ECPG_INFORMIX_H
 #define _ECPG_INFORMIX_H
@@ -82,11 +82,6 @@ extern int	dttofmtasc(timestamp *, char *, int, char *);
 extern int	intoasc(interval *, char *);
 extern int	dtcvfmtasc(char *, char *, timestamp *);
 
-/* we also define Informix datatypes here */
-typedef timestamp dtime_t;
-typedef interval intrvl_t;
-typedef decimal dec_t;
-
 #ifdef __cplusplus
 }
 #endif

src/interfaces/ecpg/preproc/pgc.l

@@ -12,7 +12,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/interfaces/ecpg/preproc/pgc.l,v 1.160 2008/02/14 12:22:36 meskes Exp $
+ *	  $PostgreSQL: pgsql/src/interfaces/ecpg/preproc/pgc.l,v 1.161 2008/02/14 12:27:26 meskes Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1320,7 +1320,7 @@ static bool isdefine(void)
 
 static bool isinformixdefine(void)
 {
-/*	const char *new = NULL;
+	const char *new = NULL;
 
 	if (strcmp(yytext, "dec_t") == 0)
 		new = "decimal";
@@ -1344,7 +1344,7 @@ static bool isinformixdefine(void)
 		yy_scan_string(new);
 		return true;
 	}
-*/
+
 	return false;
 }