Use Cwd::realpath instead of rel2abs because rel2abs doesn't work

Author: donaldh

ConfigureJVM.pl

@@ -6,8 +6,7 @@
 use warnings;
 use Text::ParseWords;
 use Getopt::Long;
-use File::Spec;
-use Cwd;
+use Cwd qw(cwd realpath);
 use lib "tools/lib";
 use NQP::Configure qw(fill_template_file fill_template_text
                       slurp system_or_die sorry);
@@ -33,7 +32,7 @@
     }
 
     my $prefix = $options{'prefix'} || cwd().'/install';
-    $prefix    = File::Spec->rel2abs($prefix);
+    $prefix    = realpath($prefix);
 
     # Save options in config.status
     unlink('config.status');