Store current LC_COLLATE and LC_CTYPE settings in pg_control during initdb;

re-adopt these settings at every postmaster or standalone-backend startup.
This should fix problems with indexes becoming corrupt due to failure to
provide consistent locale environment for postmaster at all times.  Also,
refuse to start up a non-locale-enabled compilation in a database originally
initdb'd with a non-C locale.  Suppress LIKE index optimization if locale
is not "C" or "POSIX" (are there any other locales where it's safe?).
Issue NOTICE during initdb if selected locale disables LIKE optimization.

src/backend/postmaster/postmaster.c

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.191 2000/11/25 19:05:42 petere Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.192 2000/11/25 20:33:52 tgl Exp $
  *
  * NOTES
  *
@@ -617,13 +617,11 @@ PostmasterMain(int argc, char *argv[])
 	}
 #endif
 
+	XLOGPathInit();
+
 	/* set up shared memory and semaphores */
 	reset_shared(PostPortNumber);
 
-	/* Init XLOG paths */
-	snprintf(XLogDir, MAXPGPATH, "%s/pg_xlog", DataDir);
-	snprintf(ControlFilePath, MAXPGPATH, "%s/global/pg_control", DataDir);
-
 	/*
 	 * Initialize the list of active backends.	This list is only used for
 	 * garbage collecting the backend processes.