Since PERL_PATH can expand to "/usr/bin/env perl", adding an option after it
isn't portable.

diff -x config.log -x config.status -ru tmp/glib-2.26.1/gobject/glib-mkenums.in work/glib-2.26.1/gobject/glib-mkenums.in
--- tmp/glib-2.26.1/gobject/glib-mkenums.in     2010-05-14 03:21:51.000000000 +0100
+++ work/glib-2.26.1/gobject/glib-mkenums.in    2011-02-04 11:05:39.000000000 +0000
@@ -1,5 +1,6 @@
-#!@PERL_PATH@ -w
+#!@PERL_PATH@
 
+use warnings;
 use File::Basename;
 use Safe;
 
