In flex --version test, redirect stdin to /dev/null, because some lex' hang

waiting for input.  From Pete Forman <gsez020@kryten.bedford.waii.com>.

config/programs.m4

-# $Header: /cvsroot/pgsql/config/programs.m4,v 1.1 2000/08/28 11:53:13 petere Exp $
+# $Header: /cvsroot/pgsql/config/programs.m4,v 1.2 2000/10/26 16:28:00 petere Exp $
 
 
 # PGAC_PATH_FLEX
@@ -22,7 +22,7 @@ else
     for pgac_prog in flex lex; do
       pgac_candidate="$pgac_dir/$pgac_prog"
       if test -f "$pgac_candidate" \
-        && $pgac_candidate --version >/dev/null 2>&1
+        && $pgac_candidate --version </dev/null >/dev/null 2>&1
       then
         echo '%%'  > conftest.l
         if $pgac_candidate -t conftest.l 2>/dev/null | grep FLEX_SCANNER >/dev/null 2>&1; then

configure

@@ -2550,7 +2550,7 @@ INSTALL_SHLIB="\${INSTALL} $INSTL_SHLIB_OPTS"
 
 
 
-for ac_prog in mawk gawk nawk awk
+for ac_prog in gawk mawk nawk awk
 do
 # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
@@ -2602,7 +2602,7 @@ else
     for pgac_prog in flex lex; do
       pgac_candidate="$pgac_dir/$pgac_prog"
       if test -f "$pgac_candidate" \
-        && $pgac_candidate --version >/dev/null 2>&1
+        && $pgac_candidate --version </dev/null >/dev/null 2>&1
       then
         echo '%%'  > conftest.l
         if $pgac_candidate -t conftest.l 2>/dev/null | grep FLEX_SCANNER >/dev/null 2>&1; then