add .evaluate_unquotes to BVal and Block

src/QAST/BVal.nqp

@@ -1,4 +1,8 @@
 class QAST::BVal is QAST::Node {
     has $!value;
     method value(*@value) { $!value := @value[0] if @value; $!value }
+
+    method evaluate_unquotes(@unquotes) {
+        self
+    }
 }

src/QAST/Block.nqp

@@ -41,4 +41,15 @@ class QAST::Block is QAST::Node {
     method symtable() {
         %!symbol
     }
+
+    method evaluate_unquotes(@unquotes) {
+        my $result := pir::repr_clone__PP(self);
+        my $i := 0;
+        my $elems := +@(self);
+        while $i < $elems {
+            $result[$i] := self[$i].evaluate_unquotes(@unquotes);
+            $i := $i + 1;
+        }
+        $result
+    }
 }