add missing file for perl.

src/interfaces/perl5/Makefile.PL.in

+#-------------------------------------------------------
+#
+# $Id: Makefile.PL.in,v 1.1 1998/10/16 05:58:22 momjian Exp $
+#
+# Copyright (c) 1997, 1998  Edmund Mergl
+#
+#-------------------------------------------------------
+
+use ExtUtils::MakeMaker;
+use Config;
+use strict;
+
+my %opts;
+
+if (! $ENV{POSTGRES_HOME}) {
+
+    my $cwd = `pwd`;
+    chop $cwd;
+
+    %opts = (
+        NAME         => 'Pg',
+        VERSION_FROM => 'Pg.pm',
+        INC          => "-I$cwd/../libpq -I$cwd/../../include",
+        OBJECT       => "Pg\$(OBJ_EXT)",
+        LIBS         => ["-L@prefix@/lib -L$cwd/../libpq -lpq"],
+    );
+
+} else {
+
+    %opts = (
+        NAME         => 'Pg',
+        VERSION_FROM => 'Pg.pm',
+        INC          => "-I$ENV{POSTGRES_HOME}/include",
+        OBJECT       => "Pg\$(OBJ_EXT)",
+        LIBS         => ["-L$ENV{POSTGRES_HOME}/lib -lpq"],
+    );
+}
+
+
+WriteMakefile(%opts);
+
+exit(0);
+
+# end of Makefile.PL