Add Win32 versions of unlink and rename --- loop until success.

src/include/c.h

@@ -12,7 +12,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: c.h,v 1.138 2003/04/18 01:03:42 momjian Exp $
+ * $Id: c.h,v 1.139 2003/04/22 02:18:09 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -711,6 +711,17 @@ int fseeko(FILE *stream, off_t offset, int whence);
 off_t ftello(FILE *stream);
 #endif
 
+/*
+ * Win32 doesn't have reliable rename/unlink during concurrent access
+ */
+#ifdef WIN32
+int pgrename(const char *from, const char *to);
+int pgunlink(const char *path);      
+#define rename(path)		pgrename(path)
+#define unlink(from, to)	pgunlink(from, to)
+#endif
+
+  
 /* These are for things that are one way on Unix and another on NT */
 #define NULL_DEV		"/dev/null"