Fix Hash.perl creating code that throws an error when EVALing

.perl on an empty, itemized hash generated ${} which throws an error about
${} no longer being the correct syntax and using $() instead.
{}.item means the same and is EVALable

src/core/Hash.pm

@@ -44,8 +44,8 @@ my class Hash { # declared in BOOTSTRAP
     }
 
     multi method perl(Hash:D \SELF:) {
-        '$' x nqp::iscont(SELF) ~
         '{' ~ SELF.pairs.sort.map({.perl}).join(', ') ~ '}'
+        ~ '.item' x nqp::iscont(SELF)
     }
 
     multi method gist(Hash:D:) {