Make 'dummy' declarations in header files be 'extern int no_such_variable'

instead of 'extern int errno'; the latter is unsafe according to the
ANSI C standard, as well as in practice on some platforms.

src/include/catalog/indexing.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: indexing.h,v 1.75 2002/09/04 20:31:37 momjian Exp $
+ * $Id: indexing.h,v 1.76 2002/10/18 20:33:57 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -98,8 +98,8 @@ extern void CatalogUpdateIndexes(Relation heapRel, HeapTuple heapTuple);
  * These macros are just to keep the C compiler from spitting up on the
  * upcoming commands for genbki.sh.
  */
-#define DECLARE_INDEX(x) extern int errno
-#define DECLARE_UNIQUE_INDEX(x) extern int errno
+#define DECLARE_INDEX(x) extern int no_such_variable
+#define DECLARE_UNIQUE_INDEX(x) extern int no_such_variable
 #define BUILD_INDICES
 
 

src/include/postgres.h

@@ -10,7 +10,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1995, Regents of the University of California
  *
- * $Id: postgres.h,v 1.61 2002/09/04 20:31:36 momjian Exp $
+ * $Id: postgres.h,v 1.62 2002/10/18 20:33:57 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -539,8 +539,8 @@ extern int ExceptionalCondition(char *conditionName, char *errorType,
 #define BKI_WITHOUT_OIDS
 
 /* these need to expand into some harmless, repeatable declaration */
-#define DATA(x)   extern int errno
-#define DESCR(x)  extern int errno
+#define DATA(x)   extern int no_such_variable
+#define DESCR(x)  extern int no_such_variable
 
 #define BKI_BEGIN
 #define BKI_END

src/pl/plperl/ppport.h

@@ -177,11 +177,7 @@ __DATA__
 #endif
 
 #ifndef dTHR
-#ifdef WIN32
-#define dTHR extern int Perl___notused
-#else
-#define dTHR extern int errno
-#endif
+#define dTHR extern int no_such_variable
 #endif
 
 #ifndef boolSV