New interpolation: %x --> $^X (current Perl interpreter)

Changes

@@ -1,5 +1,8 @@
 Revision history for Perl module Alien::Base.
 
+0.000_015
+	- interpolation %x is current Perl interpreter ($^X)
+
 0.000_014  May 1, 2012
 	- bugfix on dontpanic build chain (t/zz-example.t)
 

lib/Alien/Base/ModuleBuild.pm

@@ -384,6 +384,8 @@ sub alien_interpolate {
   $string =~ s/(?<!\%)\%p/$prefix/g;
   #   library name (ph: %n)
   $string =~ s/(?<!\%)\%n/$name/g;
+  #   current interpreter ($^X) (ph: %x)
+  $string =~ s/(?<!\%)\%x/$^X/g;
 
   #remove escapes (%%)
   $string =~ s/\%(?=\%)//g;

lib/Alien/Base/ModuleBuild/API.pod

@@ -188,6 +188,10 @@ Shortcut for the name stored in C<alien_name>
 
  pkg-config --modversion %n
 
+=item %x
+
+The current Perl interpreter (aka $^X)
+
 =item %%
 
 A literal C<%>.

t/interpolate.t

@@ -18,5 +18,7 @@ my $path = rel2abs "_install";
 is( $builder->alien_interpolate('thing other=%s'), "thing other=$path", 'share_dir interpolation');
 is( $builder->alien_interpolate('thing other=%%s'), 'thing other=%s', 'no share_dir interpolation with escape');
 
+is( $builder->alien_interpolate('%x'), "$^X", '%x is current interpreter' );
+
 done_testing;