Preparations for positional/associative delegate.

This work will eliminate some of the v-table use that is in the way of
certain bits of porting work, but should also provide some other wins.

src/NQP/Actions.pm

@@ -709,6 +709,7 @@ class NQP::Actions is HLL::Actions {
         my $sigil := $<variable><sigil>;
         my $name := $past.name;
         my $BLOCK := $*W.cur_lexpad();
+        my $*DECLARAND_ATTR;
         if $name && $BLOCK.symbol($name) {
             $/.CURSOR.panic("Redeclaration of symbol ", $name);
         }
@@ -735,7 +736,7 @@ class NQP::Actions is HLL::Actions {
             }
 
             # Add it.
-            $*W.pkg_add_attribute($*PACKAGE, %*HOW{$*PKGDECL ~ '-attr'},
+            $*DECLARAND_ATTR := $*W.pkg_add_attribute($*PACKAGE, %*HOW{$*PKGDECL ~ '-attr'},
                 %lit_args, %obj_args);
 
             $past := QAST::Stmts.new();
@@ -1179,6 +1180,12 @@ class NQP::Actions is HLL::Actions {
                 $*W.pkg_add_parrot_vtable_handler_mapping($package, $name, ~$match<variable>);
             };
         }
+        elsif $<longname> eq 'positional_delegate' {
+            $*DECLARAND_ATTR.positional_delegate(1);
+        }
+        elsif $<longname> eq 'associative_delegate' {
+            $*DECLARAND_ATTR.associative_delegate(1);
+        }
         elsif $<longname> eq 'export' {
             make -> $match {
                 my $ast  := $match.ast;

src/NQP/World.pm

@@ -409,6 +409,7 @@ class NQP::World is HLL::World {
     method pkg_add_attribute($obj, $meta_attr, %lit_args, %obj_args) {
         my $attr := $meta_attr.new(|%lit_args, |%obj_args);
         $obj.HOW.add_attribute($obj, $attr);
+        $attr
     }
 
     # Adds a method to the meta-object.

src/how/NQPAttribute.pm

@@ -5,6 +5,8 @@ knowhow NQPAttribute {
     has $!box_target;
     has $!default;
     has $!has_default;
+    has $!positional_delegate;
+    has $!associative_delegate;
 
     method new(:$name!, :$box_target, *%extra) {
         my $attr := nqp::create(self);
@@ -46,6 +48,22 @@ knowhow NQPAttribute {
     method auto_viv_container() {
         $!has_default ?? $!default !! nqp::null()
     }
+
+    method set_positional_delegate($value) {
+        $!positional_delegate := $value;
+    }
+
+    method set_associative_delegate($value) {
+        $!associative_delegate := $value;
+    }
+
+    method positional_delegate() {
+        !nqp::isnull($!positional_delegate) && $!positional_delegate ?? 1 !! 0
+    }
+
+    method associative_delegate() {
+        !nqp::isnull($!associative_delegate) && $!associative_delegate ?? 1 !! 0
+    }
 
     method compose($obj) {
         $obj

src/how/NQPClassHOW.pm

@@ -277,6 +277,12 @@ knowhow NQPClassHOW {
                 if nqp::can($attr, 'auto_viv_container') {
                     %attr_info<auto_viv_container> := $attr.auto_viv_container;
                 }
+                if $attr.positional_delegate {
+                    %attr_info<positional_delegate> := 1;
+                }
+                if $attr.associative_delegate {
+                    %attr_info<associative_delegate> := 1;
+                }
                 nqp::push(@attrs, %attr_info);
             }