Adjust configure to insist on Perl version >= 5.8.3.

Previously it only checked for version >= 5.8.0, although the
documentation has said that the minimum version is 5.8.3 since
commit dea6ba939.  Per the discussion leading up to that commit,
I (tgl) left it that way intentionally because you could, at the
time, do some bare-bones stuff with 5.8.0.  But we aren't actually
testing against anything older than 5.8.3, so who knows if that's
still true.  It's pretty unlikely that anyone would care anyway,
so let's just make configure's version check match the docs.

Dagfinn Ilmari Mannsåker

Discussion: https://postgr.es/m/87y278s6iq.fsf@wibble.ilmari.org
Discussion: https://postgr.es/m/16894.1501392088@sss.pgh.pa.us

config/perl.m4

@@ -11,11 +11,11 @@ if test "$PERL"; then
   pgac_perl_version=`$PERL -v 2>/dev/null | sed -n ['s/This is perl.*v[a-z ]*\([0-9]\.[0-9][0-9.]*\).*$/\1/p']`
   AC_MSG_NOTICE([using perl $pgac_perl_version])
   if echo "$pgac_perl_version" | sed ['s/[.a-z_]/ /g'] | \
-    $AWK '{ if ([$]1 == 5 && [$]2 >= 8) exit 1; else exit 0;}'
+    $AWK '{ if ([$]1 == 5 && ([$]2 > 8 || ($[2] == 8 && [$]3 >= 3))) exit 1; else exit 0;}'
   then
     AC_MSG_WARN([
 *** The installed version of Perl, $PERL, is too old to use with PostgreSQL.
-*** Perl version 5.8 or later is required, but this is $pgac_perl_version.])
+*** Perl version 5.8.3 or later is required, but this is $pgac_perl_version.])
     PERL=""
   fi
 fi

configure

@@ -9949,14 +9949,14 @@ if test "$PERL"; then
   { $as_echo "$as_me:${as_lineno-$LINENO}: using perl $pgac_perl_version" >&5
 $as_echo "$as_me: using perl $pgac_perl_version" >&6;}
   if echo "$pgac_perl_version" | sed 's/[.a-z_]/ /g' | \
-    $AWK '{ if ($1 == 5 && $2 >= 8) exit 1; else exit 0;}'
+    $AWK '{ if ($1 == 5 && ($2 > 8 || ($2 == 8 && $3 >= 3))) exit 1; else exit 0;}'
   then
     { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING:
 *** The installed version of Perl, $PERL, is too old to use with PostgreSQL.
-*** Perl version 5.8 or later is required, but this is $pgac_perl_version." >&5
+*** Perl version 5.8.3 or later is required, but this is $pgac_perl_version." >&5
 $as_echo "$as_me: WARNING:
 *** The installed version of Perl, $PERL, is too old to use with PostgreSQL.
-*** Perl version 5.8 or later is required, but this is $pgac_perl_version." >&2;}
+*** Perl version 5.8.3 or later is required, but this is $pgac_perl_version." >&2;}
     PERL=""
   fi
 fi