RakuAST: Have try fatalize a returned Failure

The try statement prefix is supposed to fatalize returned Failures, i.e.
have them be thrown as exceptions, so they will be caught by the
generated CATCH block and stored in $!.

src/Raku/ast/statementprefixes.rakumod

@@ -115,7 +115,8 @@ class RakuAST::StatementPrefix::Try is RakuAST::StatementPrefix is RakuAST::Sink
     method PRODUCE-IMPLICIT-LOOKUPS() {
         self.IMPL-WRAP-LIST([
             RakuAST::Type::Setting.new(RakuAST::Name.from-identifier('Nil')),
-            RakuAST::Var::Lexical.new('$!')
+            RakuAST::Var::Lexical.new('$!'),
+            RakuAST::Type::Setting.new(RakuAST::Name.from-identifier('Failure')),
         ])
     }
 
@@ -131,20 +132,41 @@ class RakuAST::StatementPrefix::Try is RakuAST::StatementPrefix is RakuAST::Sink
             my @lookups := self.IMPL-UNWRAP-LIST(self.get-implicit-lookups);
             my $nil := @lookups[0].IMPL-TO-QAST($context);
             my $bang := @lookups[1].IMPL-TO-QAST($context);
+            my $Failure := @lookups[2].IMPL-TO-QAST($context);
+            my $tmp := QAST::Node.unique('fatalizee');
+            my $qast := self.IMPL-CALLISH-QAST($context);
             QAST::Op.new(
                 :op('handle'),
 
                 # Success path puts Nil into $! and evaluates to the block.
                 QAST::Stmt.new(
                     :resultchild(0),
-                    self.IMPL-CALLISH-QAST($context),
-                    QAST::Op.new( :op('p6assign'), $bang, $nil )
+                    QAST::Stmts.new(
+                        :resultchild(0),
+                        QAST::Op.new(
+                            :op('bind'),
+                            QAST::Var.new( :name($tmp), :scope('local'), :decl('var') ),
+                            $qast
+                        ),
+                        QAST::Op.new(
+                            :op('if'),
+                            QAST::Op.new(
+                                :op('istype'),
+                                QAST::Var.new( :name($tmp), :scope('local') ),
+                                $Failure,
+                            ),
+                            QAST::Op.new(
+                                :op('callmethod'), :name('sink'),
+                                QAST::Var.new( :name($tmp), :scope('local') )
+                            )
+                        )),
+                    QAST::Op.new( :op('p6store'), $bang, $nil )
                 ),
 
                 # On failure, capture the exception object into $!.
                 'CATCH', QAST::Stmts.new(
                     QAST::Op.new(
-                        :op('p6assign'),
+                        :op('p6store'),
                         $bang,
                         QAST::Op.new(
                             :name<&EXCEPTION>, :op<call>,