THRIFT-199: integrate perl into automake

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@739697 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 3cb592c..5581ce0 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -21,13 +21,16 @@
 SUBDIRS += rb
 endif
 
+if WITH_PERL
+SUBDIRS += perl
+endif
+
 # All of the libs that don't use Automake need to go in here
 # so they will end up in our release tarballs.
 EXTRA_DIST = \
   cocoa \
   hs    \
   ocaml \
-  perl  \
   php   \
   erl   \
   st