Kludge <dl> handling in older rakudos

Fixes #43

META6.json

@@ -1,7 +1,7 @@
 {
     "perl"        : "6.*",
     "name"        : "Pod::To::HTML",
-    "version"     : "0.3.21",
+    "version"     : "0.3.22",
     "description" : "Convert Perl 6 Pod to HTML",
     "license"     : "Artistic-2.0",
     "depends"     : ["URI"],

lib/Pod/To/HTML.pm

@@ -84,7 +84,7 @@ multi visit($root, :&pre, :&post, :&assemble = -> *% { Nil }) {
 
 class Pod::List is Pod::Block { };
 class Pod::DefnList is Pod::Block { };
-
+BEGIN { if ::('Pod::Defn') ~~ Failure { CORE::Pod::<Defn> := class {} } }
 
 
 sub assemble-list-items(:@content, :$node, *% ) {

t/075-defn.t

@@ -1,8 +1,13 @@
 #!perl6
 
 use Test;
+
+# do NOT move this below `Pod::To::HTML` line, the module exports a fake Pod::Defn
+constant no-pod-defn = ::('Pod::Defn') ~~ Failure;
+
 use Pod::To::HTML;
 
+plan :skip-all<Compiler does not support Pod::Defn> if no-pod-defn;
 plan 1;
 
 =begin pod