Revert "THRIFT-5501 Remove Common Lisp support"

This reverts commit d88d4f93b3390989bd47a43f3941ca7d576750f6.
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 64b9030..3f717f1 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -92,6 +92,10 @@
 SUBDIRS += rs
 endif
 
+if WITH_CL
+SUBDIRS += cl
+endif
+
 if WITH_SWIFT
 SUBDIRS += swift
 endif